Liquid crystal display device, alignment film, and methods for manufacturing the same

ABSTRACT

An alignment film includes a first pre-tilt functional group, a second pre-tilt functional group and a first vertical alignment functional group, which are linked to polysiloxane on a substrate. The first vertical alignment functional group includes a cyclic compound and is aligned substantially perpendicularly to the substrate. The first pre-tilt functional group is cross-linked to the second pre-tilt functional group and tilted with respect to the substrate.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. §119(a) to a KoreanPatent Application Serial No. 10-2011-0107357 filed on Oct. 20, 2011,the disclosure of which is hereby incorporated by reference herein inits entirety.

TECHNICAL FIELD

The present disclosure relates to a liquid crystal display device, analignment film, and methods for manufacturing the same

DISCUSSION OF THE RELATED ART

In general, liquid crystal display devices may be classified into, forexample, a twisted nematic-type device, a horizontal electric field-typedevice, and a vertical alignment-type device according to thecharacteristics of a liquid crystal layer. A Patterned VerticallyAligned (PVA) mode, e.g., the vertical alignment-type approach, has beendeveloped to realize a wide viewing angle. To further increase the sidevisibility of the PVA mode, a micro-slit mode and a Super VerticalAlignment (SVA) mode have been developed. In the SVA mode, a reactivemesogen may exist in a liquid crystal layer to align liquid crystalmolecules. The reactive mesogen may exist in the liquid crystal layerwithout being cured or hardened. If light is irradiated thereto, thereactive mesogen may be cured, thereby pre-tilting the liquid crystalmolecules. Depending on the pre-tilt angle of the liquid crystalmolecules, a response time of the liquid crystal display device may bechanged and light leakage defects may occur.

Therefore, an alignment film for optimizing the pre-tilt angle of theliquid crystal molecules may be required. To increase thecharacteristics and reliability of the alignment film, a materialforming the alignment film should include various functional groups.

SUMMARY OF THE INVENTION

An exemplary embodiment of the present invention may provide a liquidcrystal display device having a fast response time and reduced lightleakage defects.

An exemplary embodiment of the present invention may provide analignment film having a high reliability.

In accordance with an exemplary embodiment of the present invention, analignment film includes a first pre-tilt functional group, a secondpre-tilt functional group and a first vertical alignment functionalgroup, which are linked to polysiloxane on a substrate. The firstvertical alignment functional group includes a cyclic compound and isaligned substantially perpendicularly to the substrate. The firstpre-tilt functional group is cross-linked to the second pre-tiltfunctional group and tilted with respect to the substrate.

A mol % composition ratio of the first vertical alignment functionalgroup and the first pre-tilt functional group may be about 1:about 1.5to about 11.

The first vertical alignment functional group may include any one of analkyl benzene group, a cholesteric group, an alkylated alicyclic group,or an alkylated aromatic group.

The first pre-tilt functional group may be greater than the secondpre-tilt functional group in chain length.

The first and second pre-tilt functional groups may each include adifferent one of a vinyl group, a styrene group, a methacrylate group, acinnamate group, and an acrylic group.

A mol % composition ratio of the first vertical alignment functionalgroup, the first pre-tilt functional group, and the second pre-tiltfunctional group is about 1:about 1.5 to about 11:about 1 to about 3.

The alignment film may further include a sol-gel catalyst or anaggregation inhibitor linked to the polysiloxane.

The sol-gel catalyst or the aggregation inhibitor may include any one ofan amino group and a thiol group.

A mol % composition ratio of the first vertical alignment functionalgroup, the first pre-tilt functional group, and the aggregationinhibitor may be about 1:about 1.5 to about 11:about 0.5 to about 4.

The alignment film may further include a second vertical alignmentfunctional group linked to the polysiloxane, and the second verticalalignment functional group may include no cyclic compound.

A mol % composition ratio of the first vertical alignment functionalgroup, the second vertical alignment functional group, and the firstpre-tilt functional group may be about 1:about 0.3 to about 3:about 1.5to about 11.

In accordance with an exemplary embodiment of the present invention, aliquid crystal display device includes a liquid crystal layer comprisingliquid crystal molecules and interposed between first and second displaypanels and an alignment film formed on at least one of the first andsecond display panels. The alignment layer includes a first pre-tiltfunctional group, a second pre-tilt functional group and a firstvertical alignment functional group, which are linked to polysiloxane.The first vertical alignment functional group includes a cyclic compoundand is configured to align first liquid crystal molecules among theliquid crystal molecules to be substantially perpendicularly to thefirst or second substrate. The first pre-tilt functional group iscross-linked to the second pre-tilt functional group and aligns secondliquid crystal molecules among the liquid crystal molecules to be tiltedwith respect to the first or second display panels.

In accordance with an exemplary embodiment of the present invention, amethod for forming an alignment film on a display panel is provided.

The method includes providing a display panel having an electrode formedthereon, forming a surface alignment reactant on the electrode, whereinthe surface alignment reactant comprises a first surface alignmentmaterial including a plurality of pre-tilting functional groups havingdifferent chain lengths bonded to a siloxane and a second surfacealignment material including a phase separation enhancer functionalgroup bonded to a siloxane. The first surface alignment material is avertical alignment material configured to align liquid crystalssubstantially perpendicular to a plane of the display panel.

In addition, the method further includes performing a first heatingprocess on the surface alignment reactant to cause the surface alignmentreactant to become phase separated into a surface inorganic layer and asurface functional group layer, wherein the surface inorganic layerincludes the second surface alignment material and the surfacefunctional group layer includes the first surface alignment material andirradiating the surface functional group layer to thereby form analignment layer on the electrode.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments of the present invention can be understood in moredetail from the following description taken in conjunction with theaccompanying drawings, in which:

FIG. 1 is a block diagram of a liquid crystal display device accordingto an exemplary embodiment of the present invention;

FIG. 2 schematically illustrates the structure of two subpixels in aliquid crystal display device according to an exemplary embodiment ofthe present invention;

FIG. 3 illustrates the layout of a liquid crystal display panel assemblyaccording to an exemplary embodiment of the present invention;

FIG. 4A is a cross-sectional view taken along line 4 a-4 a′ of theliquid crystal display panel assembly shown in FIG. 3;

FIG. 4B is a cross-sectional view taken along line 4 b-4 b′ of theliquid crystal display panel assembly shown in FIG. 3;

FIG. 4C is a cross-sectional view taken along line 4 c-4 c′ of theliquid crystal display panel assembly shown in FIG. 3;

FIG. 5A is an enlarged plan view of the central part A5 of the secondsubpixel electrode 191 l shown in FIG. 3;

FIG. 5B is an enlarged plan view illustrating another example of thesubpixel electrode shown in FIG. 5A;

FIG. 6A is a flowchart illustrating a method for manufacturing a liquidcrystal display panel assembly based on the SVA mode using lower andupper display panels manufactured in accordance with FIGS. 1 to 5B;

FIG. 6B is a flowchart illustrating a method for manufacturing a liquidcrystal display panel assembly based on a Surface-Controlled VerticalAlignment (SC-VA) mode using lower and upper display panels manufacturedin accordance with FIGS. 1 to 5B;

FIG. 6C is a flowchart illustrating a method for manufacturing a liquidcrystal display panel assembly based on a polarized Ultra-VioletVertical-Alignment (UV-VA) mode using lower and upper display panelsmanufactured in accordance with FIGS. 1 to 5B;

FIG. 7A is a waveform diagram for providing a DC voltage to a liquidcrystal display panel assembly;

FIG. 7B is a waveform diagram for providing a multi-step voltage to aliquid crystal display panel assembly;

FIGS. 8A to 8E sequentially illustrate a process of forming a surfacephoto hardener layer and a main alignment film of a liquid crystaldisplay panel assembly based on the SC-VA mode in accordance with anexemplary embodiment of the present invention;

FIG. 9 conceptually illustrates a step of forming a photo hardeninglayer by hardening a surface photo hardener layer;

FIG. 10 illustrates Scanning Electron Microscope (SEM) images obtainedby photographing one pixel PX of a liquid crystal display device havingthe SC-VA mode's characteristics over the time;

FIG. 11 illustrates an equivalent circuit for one pixel of a liquidcrystal display device according to an exemplary embodiment of thepresent invention;

FIG. 12 is a plan view of pixel electrodes in a basic pixel group of aliquid crystal display device according to an exemplary embodiment ofthe present invention;

FIG. 13A is a gray level-luminance ratio graph of a conventional liquidcrystal display device;

FIG. 13B is a gray level-luminance ratio graph of a proposed liquidcrystal display device;

FIG. 14 is a plan view of pixel electrodes in a basic pixel group of aliquid crystal display device according to an exemplary embodiment ofthe present invention;

FIGS. 15A to 15G sequentially illustrate a process of forming analignment film of a liquid crystal display panel assembly according toan exemplary embodiment (UV-VA mode) of the present invention;

FIGS. 16A to 16G illustrate basic shapes of micro branches and microslits;

FIGS. 17A to 17G illustrate other examples of the subpixel electrodeshown in FIGS. 5A and 5B;

FIG. 18 is a schematic layout of one pixel according to an exemplaryembodiment of the present invention;

FIG. 19A is an enlarged view of the central part A19 of the pixel shownin FIG. 18;

FIG. 19B is an enlarge view of the portion A19 shown in FIG. 18 in eachof the pixels in a basic pixel group;

FIGS. 20A to 20C illustrate patterns of main layers constituting thepixel shown in FIG. 18, in which FIG. 20A illustrates a pattern of agate layer conductor, FIG. 20B illustrates a pattern of a data layerconductor, and FIG. 20C illustrates a pattern of a pixel electrodelayer;

FIGS. 20D and 20E illustrate other examples of the pattern of the pixelelectrode layer shown in FIGS. 18 and 20C, respectively;

FIGS. 20F to 20J are plan views of pixel electrodes according to anexemplary embodiment of the present invention;

FIGS. 21A and 21B are cross-sectional views taken along lines 21 a-21 a′and 21 b-21 b′ of the pixel shown in FIG. 18, respectively;

FIGS. 22A to 22H are cross-sectional views of a liquid crystal displaypanel assembly according to an exemplary embodiment of the presentinvention, respectively, when they are taken along line 21 a-21 a′ ofthe pixel shown in FIG. 18;

FIGS. 23A to 23F are plan views of a lower display panel for improvingunrestoration and light leakage defects of a liquid crystal displaydevice according to an exemplary embodiment of the present invention;

FIGS. 24A to 24T are plan views showing a part of a pixel electrodelayer for improving unrestoration and light leakage defects of a liquidcrystal display device according to an exemplary embodiments of thepresent invention;

FIG. 25 illustrates a schematic layout of one pixel according to anexemplary embodiment of the present invention;

FIGS. 26A to 26C illustrate patterns of main layers constituting thepixel shown in FIG. 25, in which FIG. 26A illustrates a pattern of agate layer conductor, FIG. 26B illustrates a pattern of a data layerconductor, and FIG. 26C illustrates a pattern of a pixel electrodelayer;

FIGS. 27A and 27B are cross-sectional views taken along lines 27 a-27 a′and 27 b-27 b′ of the pixel shown in FIG. 25, respectively;

FIG. 28 is a plan view of pixel electrodes in a basic pixel group of aliquid crystal display device according to an exemplary embodiment ofthe present invention;

FIG. 29 is a plan view of pixel electrodes in a basic pixel group of aliquid crystal display device according to an exemplary embodiment ofthe present invention;

FIG. 30 is a plan view of pixel electrodes in a basic pixel group of aliquid crystal display device according to an exemplary embodiment ofthe present invention;

FIG. 31 is a plan view of pixel electrodes in a basic pixel group of aliquid crystal display device according to an exemplary embodiment ofthe present invention;

FIG. 32 is a plan view of pixel electrodes in a basic pixel group of aliquid crystal display device according to an exemplary embodiment ofthe present invention; and

FIGS. 33A to 33I illustrate shapes and splitting structures of pixelelectrodes constituting a liquid crystal display device.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Exemplary embodiments of the present invention will now be described indetail with reference to the accompanying drawings.

In this specification, the same drawing reference numerals will beunderstood to refer to the same elements, features and structures. Inthe drawings, the thickness of layers, films, panels, regions, etc., maybe exaggerated for clarity. It will be understood that when an elementsuch as, for example, a layer, film, region, or substrate is referred toas being “on”, “connected to” or “coupled to” another element, it can bedirectly on, connected to or coupled to the other element or interveningelements may also be present. Like reference numerals designate likeelements throughout the specification.

As used herein, the singular forms, “a”, “an”, and “the” are intended toinclude plural forms as well, unless the context clearly indicatesotherwise.

A liquid crystal display device according to an exemplary embodiment ofthe present invention will be described in detail with reference toFIGS. 1 and 2. FIG. 1 is a block diagram of a liquid crystal displaydevice according to an exemplary embodiment of the present invention.FIG. 2 schematically illustrates the structure of two subpixels 190 hand 190 l constituting one pixel PX in a liquid crystal display deviceaccording to an exemplary embodiment of the present invention. Asillustrated in FIG. 1, the liquid crystal display device includes, forexample, a liquid crystal display panel assembly 300, a gate driver 400,a data driver 500, a signal controller 600, and a gray level voltagegenerator 800.

The signal controller 600 receives control signals from a host (notshown), which include, for example, video signals R, G and B, a dataenable signal DE, horizontal and vertical synchronization signals Hsyncand Vsync, and a clock signal MCLK. The signal controller 600 outputsdata control signals CONT2 and video data signals DAT to the data driver500, and outputs gate control signals CONT1 for selecting gate lines, tothe gate driver 400. The signal controller 600 may output light sourcecontrol signals to a light source generator (not shown) to adjust thelight source.

The gray level voltage generator 800 generates all gray level voltagesor a limited number of gray level voltages (hereinafter referred to as‘reference gray level voltages’), which are provided to pixels PX, andoutputs them to the data driver 500. The reference gray level voltage isdifferent from the common voltage Vcom in polarity.

The data driver 500 receives a reference gray level voltage from thegray level voltage generator 800, and outputs gray level voltages to aplurality of data lines D₁-D_(m) in response to the data control signalsCONT2 and the video data signals DAT from the signal controller 600.When the gray level voltage generator 800 provides only a limited numberof reference gray level voltages, the data driver 500 may generate alarger number of extended gray level voltages by dividing the referencegray level voltages. When providing the extended gray level voltages tothe data lines D₁-D_(m), the data driver 500 performs inversion drivingof alternately applying a voltage having the same difference but adifferent polarity with respect to the common voltage Vcom in everyframe, to each of the pixels. The inversion driving methods may beclassified into, for example, frame inversion in which data voltages aresupplied such that data voltages applied to all pixels are the same inpolarity in one frame and data voltage's polarities of all pixels areinversed in the next frame, column inversion in which data voltages aresupplied such that polarities of the data voltages applied to pixels onthe adjacent data lines D₁˜D_(m) are inversed in one frame, pointinversion in which data voltages are supplied such that voltagepolarities of adjacent pixels PX are different from each other and 2+1inversion in which data voltages are supplied such that two pixels PXadjacent to the same data line D₁˜D_(m) (171) have the same polarity andone pixel PX adjacent to the two pixels PX having the same polarity hasa different polarity in a repeated manner.

The gate driver 400 sequentially outputs gate signals to a plurality ofgate lines G₁-G_(n) in response to the gate control signals CONT1. Thegate signal has a gate-on voltage Von capable of turning on Thin FilmTransistors (TFTs) connected to a selected gate line, and a gate-offsignal Voff capable of turning off TFTs connected to unselected gates.

The liquid crystal display panel assembly 300 includes, for example, alower display panel 100, an upper display panel 200 facing the lowerdisplay panel 100, and a liquid crystal layer 3 interposed between thelower display panel 100 and the upper display panel. The lower displaypanel 100 has pixels PX arranged in the form, for example, of a matrixof rows and columns, multiple gate lines G₁˜G_(n) (121) to which pixelsPX on the same rows are connected, and multiple data lines D₁˜D_(m)(171) to which pixels PX on the same columns are connected. FIG. 2illustrates the schematic structure of one pixel PX among the multiplepixels PX shown in FIG. 1. One pixel PX is divided into, for example, apair of a first subpixel 190 h and a second subpixel 190 l spaced apartfrom each other. First and second subpixel electrodes 191 h and 191 lare formed in areas of the first and second subpixels 190 h and 190 l,respectively. The subpixels 190 h and 190 l have liquid crystalcapacitors Clch and Clcl, and storage capacitors Csth and Cstl,respectively. Each of the liquid crystal capacitors Clch and Clcl isformed by the liquid crystal layer 3 interposed between one terminal ofeach of the subpixel electrodes 191 h and 191 l formed on the lowerdisplay panel 100 and one terminal of a common electrode 270 formed onthe upper display panel 200. In an embodiment of the present invention,the subpixels 190 h and 190 l may alternatively be connected to TFTsconnected to different data lines D₁-D_(m).

The common electrode 270 is formed on the entire surface of the upperdisplay panel 200, and receives the common voltage Vcom. For example,the common electrode 270 together with the pixel electrode 191 may beformed on the lower display panel 100, and may have a line or bar shapedepending on the shape of the pixel electrode 191.

The liquid crystal layer 3 is filled in a sealant (not shown) formedbetween the lower and upper display panels 100 and 200. The liquidcrystal layer 3 serves as a dielectric. The sealant is formed on any oneof the lower and upper display panels 100 and 200, when combining orassembling the two display panels 100 and 200. The lower and upperdisplay panels 100 and 200, as shown in FIG. 4A, may maintain a cell gapof, for example, about 2.0 μm to about 5.0 μm by a spacer 250 or asealant (not shown). For example, a cell gap of about 3.3 μm to about3.7 μm, may be maintained between the lower and upper display panels 100and 200 by a spacer 250 or a sealant (not shown). In an embodiment ofthe present invention, the spacer 250 may alternatively be formed on aTFT because the area where the TFT is formed is wide.

Polarizers (not shown) may be disposed on the lower and upper displaypanels 100 and 200 such that their polarization axes or transmissionaxes may substantially cross each other perpendicularly. In other words,the polarizers may be formed, for example, on the top or bottom of thelower and upper display panels 100 and 200. Alternatively, thepolarizers may be formed on the top or bottom of only one of the lowerand upper display panels 100 and 200. In an exemplary embodiment of thepresent invention, to reduce the diffraction of the external light,refractive indexes of the polarizers may be, for example, about 1.5, andtheir haze values may be, for example, about 2% to about 5%. Therefractive indexes of the polarizers and the refractive indexes of othermaterials described below were measured in the light source with awavelength of, for example, about 550 nm to about 580 nm.

The liquid crystal display device may be manufactured by connecting thedriving devices 400, 500, 600 and 800 to the liquid crystal displaypanel assembly 300. The driving devices 400, 500, 600 and 800 may be,for example, directly mounted on the liquid crystal display panelassembly 300 after being formed on a single Integrated Circuit (IC)chip, may be attached to the liquid crystal display panel assembly 300in the form of a Tape Carrier Package (TCP) after being mounted on aFlexible Printed Circuit Film (FPCF, not shown), or may be connected tothe liquid crystal display panel assembly 300 after being mounted on aseparate Printed Circuit Board (PCB, not shown). In contrast, whilesignal lines G₁˜G_(n) and D₁˜D_(n), and TFTs Qh, Ql and Qc (shown inFIG. 3) are formed, each or a combination of their driving devices 400,500, 600 and 800 may be formed on the liquid crystal display panelassembly 300.

The principles of displaying video in the liquid crystal display devicewill be described below in brief. If a data voltage is supplied to apixel electrode of each pixel PX of the liquid crystal display device, avoltage charged in the pixel PX generates an electric field in theliquid crystal layer 3 by the voltage difference between the pixelelectrode and the common electrode 270. Because of the electric fieldformed in the liquid crystal layer 3, liquid crystal molecules 31 of theliquid crystal layer 3 are tilted or move with a directivity. The lightpassing through the liquid crystal layer 3 along the tilt or directionof the liquid crystal molecules 31 undergo phase retardation. The lightpasses through the polarizer or is absorbed into the polarizer accordingto the phase difference caused by the phase retardation of the light.Therefore, if the data voltage supplied to the pixel electrode 191 isadjusted, the light transmittance for the primary colors is changed,allowing the liquid crystal display device to render the video. Theprimary colors include colors selected from, for example, red, green,blue, cyan, magenta, yellow, and white. In accordance with an exemplaryembodiment of the present invention, the primary colors may include, forexample, red, green and blue. Alternatively, to improve the videoquality, four or more colors including the red, green, blue and yellowmay be used as the primary colors.

A liquid crystal display panel assembly 300 according to an exemplaryembodiment of the present invention will be described in detail belowwith reference to FIGS. 3 to 5B. FIG. 3 illustrates the layout of oneunit pixel constituting the liquid crystal display panel assembly 300according to an exemplary embodiment of the present invention. FIG. 4Ais a cross-sectional view taken along line 4 a-4 a′ of the liquidcrystal display panel assembly 300 shown in FIG. 3. FIG. 4B is across-sectional view taken along line 4 b-4 b′ of the liquid crystaldisplay panel assembly 300 shown in FIG. 3. FIG. 4C is a cross-sectionalview taken along line 4 c-4 c′ of the liquid crystal display panelassembly 300 shown in FIG. 3. FIG. 5A is an enlarged plan view of thecentral part A5 of the second subpixel electrode shown in FIG. 3. FIG.5B is an enlarged plan view illustrating an example of the subpixelelectrode shown in FIG. 5A. Although an enlarged plan view of one pixelis shown in FIG. 3, it should be noted that pixels may be arranged inthe form of a matrix of rows and columns.

The liquid crystal display panel assembly 300 includes, for example, alower display panel 100, an upper display panel 200, a liquid crystallayer 3, and a polarizer. The upper display panel 200 will be describedfirst in detail. The upper display panel 200 includes, for example, alight blocking member 220, an overcoat 225, a common electrode 270, andan upper-plate alignment film 292, which are formed on an uppersubstrate 210.

The light blocking member 220 is formed on the transparent uppersubstrate 210 made of, for example, a glass or plastic material. Theupper substrate 210 has a thickness of about 0.2 mm to about 0.7 mm. Theupper substrate 210 may have a refractive index of, for example, about1.0 to about 2.5, more preferably about 1.5. The light blocking member220, also called a black matrix, may be made of a metal such as chromiumoxide (CrOx), molybdenum oxide (MoOx), aluminum oxide (AlOx), titaniumoxide (TiOx), copper oxide (CuOx), and an opaque organic film material.The metal and the organic film of the light blocking member 220 have athickness of, for example, about 300 Å to about 2000 Å and about 2 μm toabout 5 μm, respectively. The light blocking member 220 has a pluralityof apertures which are similar to the pixels PX in shape so that thelight may pass through the pixels PX. The light blocking member 220 maybe formed between the pixels PX to prevent the light leakage between thepixels PX. The light blocking member 220 may be formed in the portionscorresponding to a gate line 121, a data line 171, and TFTs Qh, Ql andQc, which are formed on the lower display panel 100. In an embodiment ofthe present invention, to simplify the manufacturing process of theliquid crystal display panel assembly 300 and increase the transmittanceof the liquid crystal display device, the light blocking member 220 maybe formed on an inside of a lower substrate 110, where the gate line121, the data line 171 and the TFTs are formed, or on an outside of thelower substrate 110, where the gate line 121, the data line 171 and theTFTs are not formed.

The overcoat 225 is formed on the light blocking member 220. Theovercoat 225 planarizes the curved surface of the lower layer or lowerfilm such as the light blocking member 220, or prevents the elution ofimpurities from the lower layer. The overcoat 225 has a thickness of,for example, about 1 μm to about 3 μm. For example, the overcoat 225 mayhave a thickness of about 1.2 μm to about 1.5 μm. The overcoat 225 mayhave a refractive index of, for example, about 1.5 to about 2.5, morepreferably about 1.8. In an embodiment, when the light blocking member220 is formed on the lower display panel 100, the overcoat 225 may beformed on the light blocking member 220 formed on the lower displaypanel 100, instead of being formed on the upper display panel 200.According to an exemplary embodiment of the present invention, theovercoat 225 may include, for example, an acrylic material. The acrylicmaterial included in the overcoat 225 may be cured in a process offorming the overcoat 225. The transmittance of the short-wavelengthUltraviolet (UV) may be higher in the overcoat 225 including the curedacrylic material than in the overcoat 225 including an imide-basedmaterial. If the transmittance of the short-wavelength UV is high in theovercoat 225, the intensity or amount of light, which is incidentthereupon to cure or harden a photo hardener or reactive mesogen (RM) inthe below-described electric-field lithography or fluorescentlithography, may increase, which thereby may contribute to an increasein cross-linking rate. The acrylic material may be included in theovercoat 225 included in the below-described stacked structure of theupper plate or the lower plate.

The common electrode 270 having no multiple slits is formed on theovercoat 225. The common electrode 270 may be formed of, for example,the same material as that of the pixel electrode 191. For example, thecommon electrode 270 may be formed of a transparent conductor such asindium-tin-oxide (ITO) and indium-zinc-oxide (IZO), aluminum zinc oxide(AZO), cadmium tin oxide (CTO) silver nanowire (AgNW), gallium-dopedzinc oxide (GZO), fluorine tin oxide (FTO), antimony-doped tin oxide(ATO), zirconium oxide (ZrO2), zinc oxide (ZnO) and combinationsthereof. The common electrode 270 has a thickness of, for example, about500 Å to about 2000 Å. For example, the common electrode 270 may have athickness of about 1200 Å to about 1500 Å. The common electrode 270 maymaximize the transmittance of the liquid crystal display device. Inorder to reduce the diffraction of the external light, refractiveindexes of the common electrode 270 formed of IZO and ITO may be about1.5 to about 2.5 and about 1.5 to about 2.3, respectively. In anembodiment of the present invention, alternatively, a plurality of slitsfor forming more fringe electric fields may be formed in the commonelectrode 270.

The upper-plate alignment film 292 is formed on the common electrode 270to maintain the liquid crystal molecules 31 in a specific array. Theupper-plate alignment film 292 is formed by, for example, applying aliquid organic material having an alignment property by a method such asinkjet or roll printing, and then curing it thermally or by means of thelight source such as infrared and UV. The upper-plate alignment film 292includes, for example, an upper-plate main alignment film 34, and mayfurther include an upper-plate photo hardening layer 36. The mainalignment film 34 may be, for example, a vertical alignment materialthat substantially vertically aligns the major axis (or principal axis)of the liquid crystal molecules 31 with respect to the lower and uppersubstrates 110 and 210 or the main alignment film 34. The main alignmentfilm 34 has a thickness of, for example, about 500 Å to about 1500 Å.For example, the main alignment film 34 may have a thickness of, forexample, about 700 Å to about 1000 Å. A refractive index of the mainalignment film 34, which may increase the transmittance of the liquidcrystal display device, may be, for example, about 1.6. It will beunderstood by those of ordinary skill in the art that the main alignmentfilm 34 may be a film of the material that is generally used in aVertical Alignment (VA) mode or a Twisted Nematic (TN) mode. The photohardening layer 36 is formed of the material that is cured by the lightso that the major axis (or principal axis) of the liquid crystalmolecules 31 may have a pre-tilt angle with respect to the lower andupper substrates 110 and 210 or the main alignment film 34. The materialconstituting the photo hardening layer 36 may include, for example, aphoto hardener, a reactive mesogen, a photo-reactive polymer, aphoto-polymerizable material, or a photo-isomerizable material. Theupper-plate alignment film 292 may be a film made of, for example, atleast one material selected from a polyimide-based compound, a polyamicacid-based compound, a polysiloxane-based compound, apolyvinylcinnamate-based compound, a polyacrylate-based compound, apolymethylmethacrylate-based compound, a photo hardener, a reactivemesogen, a photo-reactive polymer, a photo-polymerizable material, aphoto-isomerizable material, and mixtures thereof. The reactive mesogenmay be, for example, acrylate, methacrylate, epoxy, oxetane,vinyl-ether, styrene, or thiolene group. The photo-reactive polymer maybe, for example, an azo-based compound, a cinnamate-based compound, achalcone-based compound, a coumarin-based compound, or a maleimide-basedcompound. The photo-polymerizable material may be, for example, chalconeor coumarin. The photo-isomerizable material may be, for example, azo ordouble tolane. The upper-plate main alignment film 34 and theupper-plate photo hardening layer 36 constituting the upper-platealignment film 292 may be formed by, for example, the methods describedbelow with reference to FIGS. 6A to 6C.

The upper-plate alignment film 292 may be a film capable of furtherincluding a photo initiator made of, for example, at least one materialselected from Benzyl dimethyl ketal (Irgacure-651, Ciba, Switzerland),α-amino acetophenone (Irgacure-907, Ciba, Switzerland), 1-hydroxycyclohexyl phenyl keton (Irgacure-184, Ciba, Switzerland), and mixturesthereof.

The material constituting the upper-plate alignment film 292 accordingto an exemplary embodiment of the present invention may be a mixture ofany one of, for example, a photo-reactive polymer and a reactivemesogen, and a polyimide-based polymer. Alternatively, the upper-platealignment film 292 may be made of, for example, the main alignment film34 except for the photo hardening layer 36.

A reactive mesogen according to an exemplary embodiment of the presentinvention will be described. The reactive mesogen forms an alignmentfilm, and is cured by light or heat to form photo hardening layers 35and 36 that will be described below. For example, chemical structure ofthe reactive mesogen may b. a photo-reactive dimethacrylate groupmonomer that is represented by the following formula XVI-R, and morespecifically, may be a monomer that is represented by any of thefollowing formulas: XVII-R1, XVII-R2, XVII-R3, XVII-R4, XVII-R5 orXVII-R6.

where A, B and C each may be any one selected from benzene ring,cyclohexyl ring and naphthalene ring. The external hydrogen atoms ofeach ring constituting A, B and C are not substituted, or at least oneof the hydrogen atoms can be substituted by alkyl group, fluorine (F),chlorine (Cl) or methoxy group (OCH₃). P1 and P2 each may be any oneselected from acrylate, methacrylate, epoxy, oxetane, vinyl-ether,styrene, and thiolene group. Z1, Z2 and Z3 each may be single bonds,linkage groups or a combination of linkage groups. A single bond meansthat A, B and C directly bond each other without intermediates. Alinkage group may be —OCO—, —COO—, alkyl group, —O— or a linkage groupwhich can be readily used by those of ordinary skill in the field of theart.

For example, the reactive mesogen may be a monomer that is representedby any one of the following formulas XVII-R1, XVII-R2, XVII-R3, XVII-R4,XVII-R5 and XVII-R6:

To evaluate the characteristics of the reactive mesogen according toexemplary embodiments of the present invention, the liquid crystaldisplay device was manufactured by applying the reactive mesogen offormula XVII-R6 among the above-described reactive mesogens. The liquidcrystal display panel assembly was manufactured based on the SVA modedescribed with reference to FIG. 6A. The structure of the pixel PX ofthe liquid crystal display device was substantially the same as that ofFIG. 3. A cell gap of the liquid crystal layer 3 was about 3.5 μm, andan illumination of the UV applied to the fluorescent lithography wasabout 0.15 mW/cm². A width of a micro branch 197 of the pixel electrode191, an exposure voltage, a UV intensity of the electric-fieldlithography, and a time of the fluorescent lithography are shown inTable 1.

TABLE 1 Width UV intensity of Time of of micro Exposure electric-fieldfluorescent branch voltage lithography lithography (μm) (V) (J/cm²)(minute) Experiment 1 3 9.5 5 60 Experiment 2 3 9.5 7 60 Experiment 3 39.5 9 60 Experiment 4 5 9.5 7 80 Experiment 5 5 9.5 7 100 Experiment 6 59.5 7 120 Experiment 7 5 9.5 7 140

The manufactured liquid crystal display device was operated by 1 Gateline 1 Data line (1G1D) driving of a charge-sharing method describedbelow with reference to FIG. 11.

In all exemplary experiments shown in Table 1, a black afterimage of theliquid crystal display device showed a level of about 2, and aninter-gray level response time was about 0.007 seconds to about 0.009seconds. Therefore, it could be understood that the reactive mesogen offormula XVII-R6 showed good characteristics even when it is applied to awide range of process conditions.

In the afterimage evaluation method, after a check pattern image isdisplayed on the liquid crystal display device for about one day or moreand then replaced with other images, the check pattern is observed andevaluated in a level of 1 to 5. A level of 1 represents a level in whichthe check pattern is not observed at a side. A level of 2 represents alevel in which the check pattern is slightly observed at a side. A levelof 3 represents a level in which the check pattern is clearly observedat a side. A level of 4 represents a level in which the check pattern isslightly observed in the front. A level of 5 represents a level in whichthe check pattern is clearly observed in the front. Evaluating the blackafterimage includes displaying a check pattern image, replacing it witha black pattern, and then observing the check pattern. Evaluating asurface afterimage includes displaying a check pattern image, replacingit with gray level patterns, and then observing the check pattern.

Lower Display Panel

The lower display panel 100 will be described in detail below. The lowerdisplay panel 100 includes thereon, for example, a gate layer conductor,which becomes a gate line 121, a down gate line 123 and a storageelectrode line 125, a gate insulating layer 140, a semiconductor 154, alinear ohmic contact member 165, a data layer conductor (171, 173, 175and 177 c), a first protection film 181, a color filter 230, a secondprotection film 182, a pixel electrode 191, and a lower-plate alignmentfilm 291.

The gate layer conductor including multiple gate lines 121, multipledown gate lines 123 and multiple storage electrode lines 125 is formedon the lower substrate 110 made of, for example, a glass or plasticmaterial. The lower substrate 110 has a thickness of, for example, about0.2 mm to about 0.7 mm. The lower substrate 110 may have a refractiveindex of, for example, about 1.0 to about 2.5. For example, the lowersubstrate 110 may have a refractive index of about 1.5. The gate line121 and the down gate line 123 extend mainly in the horizontal directionand transfer gate signals. The gate layer conductor may be formed of amaterial selected from, for example, chromium (Cr), molybdenum (Mo),titanium (Ti), aluminum (Al), copper (Cu), silver (Ag), cobalt (Co) andmixtures thereof. In an embodiment, the gate layer conductor may have asingle layer structure. Alternatively, in an embodiment, the gate layerconductor may alternatively have, for example, a double layer structureor triple layer structure. For example, the double layer structure maybe aluminum (Al)/molybdenum (Mo), aluminum (Al)/titanium (Ti), aluminum(Al)/tantalum (Ta), aluminum (Al)/nickel (Ni), aluminum (Al)/titaniumnitride (TiNx), aluminum (Al)/cobalt (Co), copper (Cu)/copper (Cu)manganese (Mn), copper (Cu)/titanium (Ti), copper (Cu)/titanium nitride(TiN), or copper (Cu)/titanium oxide (TiOx). The triple layer structuremay be, for example, molybdenum (Mo)/aluminum (Al)/molybdenum (Mo),titanium (Ti)/aluminum (Al)/titanium (Ti), cobalt (Co)/aluminum(Al)/cobalt (Co), titanium (Ti)/aluminum (Al)/titanium (Ti), titaniumnitride (TiNx)/aluminum (Al)/titanium (Ti), copper (Cu) manganese(Mn)/copper (Cu)/copper (Cu)manganese (Mn), titanium (Ti)/copper(Cu)/titanium (Ti), titanium nitride (TiNx)/copper (Cu)/titanium nitride(TiNx), or titanium oxide (TiOx)/copper (Cu)/titanium oxide (TiOx). Thegate line 121 includes, for example, first and second gate electrodes124 h and 124 l, which are formed to protrude. The down gate line 123includes, for example, a third gate electrode 124 c formed to protrude.The first and second gate electrodes 124 h and 124 l are connected toeach other, forming one protrusion. The storage electrode line 125extends in the horizontal and vertical directions to surround theperimeter of the first and second subpixel electrodes 191 h and 191 l,and transfers a predetermined voltage, for example, a common voltageVcom. In contrast, the storage electrode line 125 may transferpredetermined swing voltages having two or more levels. The storageelectrode line 125 includes multiple storage electrode line's verticalportions 128 that extend approximately perpendicularly to the gate line121, a storage electrode line's horizontal portion 127 that connectsends of the storage electrode line's vertical portions 128 to eachother, and a storage electrode line's extension portion 126 formed toprotrude from the storage electrode line's horizontal portion 127.

The gate insulating layer 140 is formed on the gate layer conductor. Thegate insulating layer 140 may be a film made of, for example, aninorganic insulating material, an organic insulating material, or anorganic/inorganic insulating material. The inorganic insulating materialmay be, for example, silicon nitride (SiNx), silicon oxide (SiOx),titanium oxide (TiO₂), alumina (Al₂O₃), zirconia (ZrO₂), siliconoxynitride (SiOxNy), yttrium oxide (Y₂O₃), hafnium oxide (HfOx),aluminum nitride (AlN), aluminum oxynitride (AlNO), barium titanate(BaTiO3), lead titanate (PbTiO₃), or a combination thereof.

The organic insulating material may be, for example, poly siloxane,phenyl siloxane, polyimide, silsesquioxane, silane, or an organicinsulating material known to those skilled in the art. Theorganic/inorganic insulating material may be a mixture of at least oneor more materials selected from the above-described inorganic andorganic insulating materials. For example, the organic insulatingmaterial of poly siloxane, and the organic/inorganic insulating materialmade of poly siloxane have high heat resistance, high lightpermeability, and excellent adhesion to other layers at about 350° C. ormore. The gate insulating layer 140 made of an inorganic insulatingmaterial may have, for example, a thickness of about 2000 Å to about4000 Å. For example, the gate insulating layer 140 made of an inorganicinsulating material may have, for example, a thickness of about 3000 Å.The gate insulating layer 140 made of an organic insulating material oran organic/inorganic insulating material may have a thickness of, forexample, about 3000 Å to about 5000 Å. For example, the gate insulatinglayer 140 made of an organic insulating material or an organic/inorganicinsulating material may have a thickness of, for example, about 4000 Å.The silicon nitride (SiNx), the silicon oxide (SiOx), the organicinsulating material, or the organic/inorganic insulating materialconstituting the gate insulating layer 140, used to increase thetransmittance of the liquid crystal display device, may have arefractive index of, for example, about 1.6 to about 2.1, about 1.35 toabout 1.65, about 1.4 to about 1.7 or about 1.4 to about 1.9,respectively. For example, the silicon nitride (SiNx), the silicon oxide(SiOx), the organic insulating material, or the organic/inorganicinsulating material constituting the gate insulating layer 140, used toincrease the transmittance of the liquid crystal display device, mayhave a refractive index of, for example, about 1.85, about 1.5, about1.55, or about 1.6, respectively. As the gate insulating layer 140 iscloser to the lower substrate 110 in terms of the refractive index, thetransmittance of the liquid crystal display device may be increased. Thegate insulating layer 140 may have a single layer structure.Alternatively, the gate insulating layer 140 may have a multi layerstructure.

The semiconductor 154 that can be made of, for example, hydrogenatedamorphous silicon, crystalline silicon, or oxide semiconductor, isformed on the gate insulating layer 140. A data line 171, a sourceelectrode 173 and a drain electrode 175 substantially overlap on thesemiconductor 154. First and second semiconductors 154 h and 154 lformed on the first and second gate electrodes 124 h and 124 l areformed to be separated from a third semiconductor 154 c formed on thethird gate electrode 124 c. The semiconductor 154 has a thickness of,for example, about 1000 Å to about 2500 Å. For example, thesemiconductor has a thickness of about 1700 Å. The oxide semiconductormay be, for example, a compound having a formula expressed inA_(X)B_(X)O_(X) or A_(X)B_(X)C_(X)O_(X), where A may be Zn or Cd, B maybe Ga, Sn or In, and C may be Zn, Cd, Ga, In or Hf. X is not zero (0),and A, B and C are different from each other. In an embodiment, theoxide semiconductor may alternatively be a material selected from thegroup comprising, for example, indium zinc oxide (InZnO), indium galliumoxide (InGaO), indium tin oxide (InSnO), zinc tin oxide (ZnSnO), galliumtin oxide (GaSnO), gallium zinc oxide (GaZnO), gallium zinc tin oxide(GaZnSnO), gallium indium zinc oxide (GalnZnO), hafnium indium zincoxide (HfInZnO), hafnium zinc tin oxide (HfZnSnO) and zinc oxide (ZnO).This oxide semiconductor is, for example, about 2 to 100 times higherthan the hydrogenated amorphous silicon in terms of the effectivemobility, contributing to the improvement in charging speed of the pixelelectrode 191.

The linear ohmic contact member 165 is formed on the semiconductor 154.The linear ohmic contact member 165 has a thickness of, for example,about 200 Å to about 500 Å. First, second and third linear ohmic contactmembers 165 h, 165 l and 165 c (not shown) are formed on the first,second and third semiconductors 154 h, 154 l and 154 c, and not formedon a channel. The linear ohmic contact member 165 may include, forexample, amorphous silicon doped with n-type or p-type impurities.Alternatively, the linear ohmic contact member 165 may include, forexample, an oxide semiconductor layer. For example, the linear ohmiccontact member 165 may include an oxide semiconductor layer thatincludes one or more of the following elements: induium (In), gallium(Ga), zinc (Zn), tin (Sn), germanium (Ge), hafnium (Hf), and arsenide(As). For example, the linear ohmic contact member 165 may include, forexample, zinc oxide (ZnO), tin oxide (SnO₂), indium oxide (In₂O₃), zincstannate (Zn₂SnO₄), gallium oxide (Ga₂O₃), and hafnium oxide (HfO₂) inthe oxide semiconductor layer.

The data layer conductor, which becomes a data line 171, a first sourceelectrode 173 h, a first drain electrode 175 h, a second sourceelectrode 173 l, a second drain electrode 175 l, a third sourceelectrode 173 c and a third drain electrode 175 c, is formed on thelinear ohmic contact member 165. The data layer conductor may be formedof, for example, the same material as that of the gate layer conductor.In an embodiment, the data layer conductor may be formed of a differentmaterial than the gate layer conductor. To increase a charging ratio ofthe pixel electrode 191 and reduce the delay in transferring datavoltages, the data layer conductor may be made of, for example, alow-resistance single-layer metal or a double or triple layer materialwith at least one layer being a metal. When the semiconductor 154 ismade of an oxide semiconductor material, the data layer conductor may beformed right on the semiconductor 154 without forming of the linearohmic contact member 165.

The data line 171 crosses the gate line 121 or the down gate line 123with the gate insulating layer 140 intervening between them. The dataline 171 is connected to the cup or U-shaped first source electrode 173h, and the cap or ∩-shaped second source electrode 173 l. End portionsof the first and second drain electrodes 175 h and 175 l are partiallysurrounded by the first and second source electrodes 173 h and 173 l,respectively. The other end portion of the second drain electrode 175 lextends from the end portion partially surrounded by the second sourceelectrode 173 l, and is connected to the U-shaped third source electrode173 c. Exemplary embodiments of the present invention are not limited tothe above mentioned shapes for the first, second and third sourceelectrodes 173 h, 173 l, 173 c but rather the first, second and thirdsource electrodes 173 h, 173 l, 173 c may be formed in various shapes.One end portion of the third drain electrode 175 c is partiallysurrounded by the third source electrode 173 c, and the other endportion 177 c thereof overlaps the storage electrode line's extensionportion 126, forming a down capacitor Cstd between them. The downcapacitor Cstd varies in capacitance according to the size of the areawhere the other end portion 177 c of the third drain electrode 175 coverlaps the storage electrode line's extension portion 126. Inaccordance with an exemplary embodiment of the present invention,primary color pixels constituting a basic pixel group may have differentcapacitances of the down capacitor Cstd, respectively. FIG. 19B is anenlarged view of the portion A19 shown in FIG. 18 in each of red, greenand blue pixels PX-R, PX-G and PX-B included in a basic pixel group,showing that the capacitances of the down capacitor Cstd are differentin the respective pixels. The red, green and blue pixels PX-R, PX-G andPX-B are similar to each other, but they are different in size of thearea AOL-B, AOL-G or AOL-R of the other end portion 177 c of the thirddrain electrode 175 c, which overlaps the storage electrode line'sextension portion 126 in each of the pixels. The overlapping area may beadjusted to adjust a ratio of a voltage of a second liquid crystalcapacitor Clcl to a voltage of a first liquid crystal capacitor Clch toabout 0.6 to about 0.9:1. To reduce the below-described occurrence of ayellowish color, the ratio of a voltage of the second liquid crystalcapacitor Clcl to a voltage of the first liquid crystal capacitor Clchmay be changed according to the pixels constituting the basic pixelgroup PS. Therefore, to allow the pixels constituting the basic pixelgroup PS to have a different power ratio, the overlapping area betweenthe other end portion 177 c of the third drain electrode 175 c and thestorage electrode line's extension portion 126 may be adjusted. Forexample, to prevent the liquid crystal display device from having ayellowish color, a voltage ratio of the blue pixel B may be greater thanor equal to a voltage ratio of the green pixel G and a voltage ratio ofthe green pixel G may be greater than or equal to a voltage ratio of thered pixel R in a basic pixel group PS including the red, green and bluepixels. The size of the overlapping area for reducing the voltage ratioin each of the pixels may be as follows.AOL-B≦AOL-G≦AOL-Rwhere AOL-B, AOL-G and AOL-R represent the sizes of the overlapping areabetween the other end portion 177 c of the third drain electrode 175 cand the storage electrode line's extension portion 126 in the blue,green and red pixels B, G and R, respectively, as shown in FIG. 19B.

The first, second and third gate electrodes 124 h, 124 l and 124 c, thefirst, second and third source electrodes 173 h, 173 l and 173 c, andthe first, second and third drain electrodes 175 h, 175 l and 175 cconstitute the first, second and third TFTs Qh, Ql and Qc, respectively,for operating one pixel PX together with the first, second and thirdsemiconductors 154 h, 154 l and 154 c. A channel layer through whichcharges move during operations of the TFTs Qh, Ql and Qc is formed inthe semiconductors 154 h, 154 l and 154 c between the source electrodes173 h, 173 l and 173 c and the drain electrodes 175 h, 175 l, 175 c.When the semiconductors 154 h, 154 l and 154 c and the data layerconductor are etched using the same mask, the data layer conductor mayhave the substantially same pattern as the semiconductor 154 and thelinear ohmic contact members 161 and 165 h formed thereunder, except forthe channel region. However, according to the etching technique, a filmof the semiconductor 154 may have portions which are uncovered by thedata layer conductor and exposed to extend from both sidewalls of thedata layer conductor by a predetermined distance of, for example, about3 μm or less.

In accordance with an exemplary embodiment of the present invention,lines of the first and second drain electrodes 175 h and 175 l connectedup to contact holes 185 h and 185 l are formed in the substantially samedirection as that of micro branches in the channel, so the texture isreduced in the pixel region, contributing to an increase in brightnessof the liquid crystal display device.

The first protection film 181 is formed on the data layer conductor. Thefirst protection film 181 may be made of, for example, theabove-described inorganic insulating material, organic insulatingmaterial, or organic/inorganic insulating material, which may constitutethe gate insulating layer 140. The first protection film 181 made of aninorganic insulating material may have a thickness of, for example,about 300 Å to about 2000 Å. For example, the first protection film 181made of an inorganic insulating material may have a thickness of, forexample, about 500 Å. The first protection film 181 made of an organicinsulating material or an organic/inorganic insulating material may havea thickness of, for example, about 25000 Å to about 35000 Å. The siliconnitride (SiNx), the silicon oxide (SiOx), the organic insulatingmaterial, or the organic/inorganic insulating material constituting thefirst protection film 181, used to increase the transmittance of theliquid crystal display device, may have a refractive index of, forexample, about 1.6 to about 2.1, about 1.35 to about 1.65, about 1.5 toabout 1.9 or about 1.5 to about 1.9, respectively. The silicon nitride(SiNx), the silicon oxide (SiOx), the organic insulating material, orthe organic/inorganic insulating material constituting the firstprotection film 181, used to increase the transmittance of the liquidcrystal display device, may have a refractive index of, for example,about 1.85, about 1.5, about 1.7 to about 1.8, or about 1.6,respectively. The color filter 230 is formed on the first protectionfilm 181. The color filter 230 is formed in the pixel region PX wherethe light is not blocked. The color filter 230 has a thickness of, forexample, about 1.5 μm to about 3 μm. The color filter 230 has arefractive index of, for example, about 1.3 to about 2.2. For example,the color filter 230 has a refractive index of about 1.6. The colorfilters 230 formed in each of the pixels PX may have one of the primarycolors, for example, red, green, blue, cyan, magenta, yellow, and white.The three primary colors such as red, green and blue (or cyan, magentaand yellow) may be used as colors of the basic pixel group PS forforming the pixels PX. A white pixel may have no color filter. The whitepixel may display the white color because the white external lightpasses through the white pixel region. The basic pixel group PS is aminimum set of pixels PX capable of representing color images. In anembodiment, the basic pixel group PS may alternatively include pixels PXeach having four or more primary colors. As an example of thisembodiment, four primary colors including the three colors of red, greenand blue, and any one of cyan, magenta, yellow and white may be selectedas colors of the basic pixel group PS. It will be understood by those ofordinary skill in the art that the primary colors of the basic pixelgroup PS are not limited to these colors and various other colors may beselected in order to increase the image quality of the liquid crystaldisplay device. The color filter 230 may be formed in most of the areaexcept for the color filter holes 233 h and 233 l formed in the placewhere the contact hole 185 is located. In contrast, to easily detectdefects of the TFTs Qh, Ql and Qc, the color filter 230 may not beformed in the place where the TFTs Qh, Ql and Qc are located. The colorfilter 230 with the same color may be formed to longitudinally extend inthe vertical direction along the neighboring data lines 171. The colorfilter 230 of an exemplary embodiment of the present invention mayalternatively be formed between the light blocking member 220 and theovercoat 225 formed on the upper display panel 200.

The second protection film 182 is formed on the color filter 230 or thefirst protection film 181. The second protection film 182 may be madeof, for example, the above-described inorganic insulating material,organic insulating material, or organic/inorganic insulating material,which may constitute the gate insulating layer 140. The secondprotection film 182 made of an inorganic insulating material may have athickness of, for example, about 300 Å to about 1500 Å. For example, thesecond protection film 182 made of an inorganic insulating material mayhave a thickness of, for example, about 400 Å to about 900 Å. The secondprotection film 182 made of an organic insulating material or anorganic/inorganic insulating material may have a thickness of, forexample, about 25000 Å to about 35000 Å. The silicon nitride (SiNx), thesilicon oxide (SiOx), the organic insulating material, or theorganic/inorganic insulating material constituting the second protectionfilm 182, used to increase the transmittance of the liquid crystaldisplay device, may have a refractive index of, for example, about 1.6to about 2.1, about 1.35 to about 1.65, about 1.5 to about 1.9, or about1.4 to about 1.9, respectively. As the second protection film 182 iscloser to the pixel electrode 191 in terms of the refractive index, thetransmittance of the liquid crystal display device may be increased. Thesecond protection film 182 may prevent the color filter 230 from beingcurled up and restraining the elution of an organic material such as asolvent from the color filter 230, thereby preventing the contaminationof the liquid crystal layer 3 and thus increasing the afterimage of theliquid crystal display device. In addition, the second protection film182 formed right on the first protection film 181 is formed relativelythick, serving as planarization. The contact holes 185 h and 185 lexposing end portions of the first and second drain electrodes 175 h and175 l, respectively, are formed in contact portions of the first andsecond protection films 181 and 182. The area of the contact holes 185 hand 185 l may be, for example, less than that of the color filter holes233 h and 233 l. Alternatively, in an embodiment, the area of thecontact holes 185 h and 185 l may be, for example, greater than or equalto the area of the color filter holes 233 h and 233 l

A pixel electrode layer is formed on the second protection film 182 asshown in FIGS. 3 to 4C. The pixel electrode layer is a conductive layerincluding, for example, subpixel electrodes 191 h and 191 l, subpixelelectrode contact portions 192 h and 192 l, cross-shaped branches 195 hand 195 l, and micro branches 197 h and 197 l, and micro slits 199 h and199 l are the portions provided by removing the conductive layer fromthe pixel electrode layer. The pixel electrode 191 may have a thicknessof, for example, about 300 Å to about 700 Å. For example, the pixelelectrode 191 may have a thickness of, for example, about 550 Å. Thepixel electrode 191 includes, for example, a first subpixel electrode191 h formed in an area of the first subpixel 190 h and a secondsubpixel electrode 191 l formed in an area of the second subpixel 190 l.The pixel electrode 191 may be formed of, for example, a transparentconductive material such as indium-tin-oxide (ITO), indium-zinc-oxide(IZO), aluminum zinc oxide (AZO), cadmium tin oxide (CTO) silvernanowire (AgNW), gallium-doped zinc oxide (GZO), fluorine tin oxide(FTO), antimony-doped tin oxide (ATO), zirconium oxide (ZrO2), zincoxide (ZnO) and combinations thereof. The pixel electrode 191 may have arefractive index of, for example, about 1.5 to about 2.5, and the ITO,and IZO may have a refractive index of, for example, about 1.8 to about2.3 and about 1.7 to about 2.0, respectively. In an exemplary embodimentof the present invention, the pixel electrode 191 made of an ITOmaterial to reduce the diffraction of the external light may be formedto have a thickness of, for example, about 400 Å. In addition, a microbranch electrode or a material having a similar refractive index to thatof the main alignment films 33 and 34 may be further formed in betweenthe below-described micro branches 197, e.g., in an area of the microslits 199. The micro branch electrode 197 or the material having asimilar refractive index to that of the main alignment films 33 and 34may be, for example, TiO₂, polyphenylenevinylene (PPV) orpolyfluorinated polyimides TiO₂ (PI-TiO₂). To reduce the external lightthat is diffracted or reflected from the surface of the pixel electrode191, the surface of the pixel electrode 191 may undergo a plasma processin an atmosphere of a gas of, for example, argon (Ar), hydrogen (H₂),oxygen (O₂), helium (He) or chlorine (Cl₂), increasing the roughnessthereof. The external light that is diffracted or reflected from thesurface of the pixel electrode 191 may be minimized and the transmittedlight may be maximized, by forming the pixel electrode 191 with amaterial having the similar refractive index to that of the materialformed on or under the pixel electrode 191. The material of thetransparent pixel electrode having the similar refractive index to thatof its upper or lower film may be, for example, nanowire (NW), zincoxide (ZnO), or conductive polymer. These materials may be used to forma pixel electrode having a refractive index of, for example, about 1.8or less. For example, nanowire (NW) is needle-like conductive particleshaving a diameter of about 10⁻⁹ m to about 10⁻⁸ m and a length of about10⁻⁷ m to about 10⁻⁶ m, and may be used to form a pixel electrode bybeing mixed with polymers. The nanowire (NW) may comprise silver (Ag),and a pixel electrode having the nanowire (NW) made of, for example,silver (Ag) may have a resistance of about 50 to 250 ohm (Ω). The firstand second subpixel electrodes 191 h and 191 l include first and secondsubpixel electrode contact portions 192 h and 192 l, cross-shaped branchportions 195 h and 195 l, vertical connection portions 193 h and 193 lsurrounding the perimeter of the subpixel electrodes 191 h and 191 l,and horizontal connection portions 194 h and 194 l, respectively. Eachof the cross-shaped branch portions 195 h and 195 l includes ahorizontal branch portion and a vertical branch portion. The first andsecond subpixel electrode contact portions 192 h and 192 l are incontact with the drain electrodes 175 h and 175 l of the first andsecond TFTs Qh and Ql through the contact holes 185 h and 185 l of thefirst and second protection films 181 and 182, respectively.

A high-definition patterning process, e.g., a process of forming microbranches 197 or micro slits 199 to have a width of about 5 μm or lessaccording to an exemplary embodiment of the present invention will bedescribed in brief. A conductive metal forming the pixel electrode layeris deposited or coated on the lower layer. A photosensitive photoresist(PR) is coated on the conductive metal. The photosensitive photoresisthas a similar pattern to that of the pixel electrode layer by thephoto-lithography process. Because the micro branches 197 or micro slits199 have a very small width, the formed pattern of the photoresist (PR)may have PR residues or some patterns may be defective. For example, tosolve this difficulty, ashing or dry etching may be performed.Thereafter, the conductive metal is etched and the photoresist (PR) isremoved, forming a pattern of the pixel electrode layer. In accordancewith an exemplary embodiment of the present invention, to implement thehigh-definition pattern by ensuring good adhesion to the lower film, thephotosensitive photoresist (PR) may include, for example, an adhesionpromoter, e.g.,bis(1,2,2,6,6-pentamethyl-4-piperidinyl)-[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]butylmalonate.In other words, the photosensitive photoresist may be manufactured bydissolving a solid including, for example, about 15 wt % to about 25 wt%, more preferably about 20 wt % of a cresol novolac resin and about 3wt % to about 7 wt %, more preferably about 5 wt % of photo-sensitizeras a matrix, and about 0.1 wt % to about 10 wt % ofbis(1,2,2,6,6-pentamethyl-4-piperidinyl)-[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]butylmalonateas an adhesion promoter in a solvent, e.g., about 65 wt % to about 74.95wt % of poly(2-glycidyl methacrylate) (PGMEA). For example, in anembodiment, the photoresist may be manufactured by dissolving a solidincluding, for example, about 20 wt % of a cresol novolac resin, about 5wt % of photo-sensitizer as a matrix, and about 0.1 wt % to about 10 wt% ofbis(1,2,2,6,6-pentamethyl-4-piperidinyl)-[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]butylmalonateas an adhesion promoter in a solvent, e.g., about 65 wt % to about 74.95wt % of poly(2-glycidyl methacrylate) (PGMEA). The cresol novolac resinmay have, for example, about 7,000 weight-average molecular weight toabout 9,000 weight-average molecular weight, and may be manufactured byperforming condensation reaction on cresol monomer in which meta-cresoland para-cresol are mixed at a ratio of, for example, about 6:4 andformaldehyde under an oxalic acid catalyst. The photo-sensitizer may be,for example, a compound manufactured by performing condensation reactionon a compound of 2,3,4,4′-tetrhydroxybenzophenone and naphthoquinone1.2-diazide-5-sulfonylchloride, or a compound manufactured by performingcondensation reaction on a compound of 4,4′,4,″-ethylidene tris phenoland naphthoquinone 1.2-diazide-5-sulfonylchloride. Because thephotoresist (PR) having this composition has good adhesion to the lowerfilm, high-definition patterns may be formed in the photo-lithographyprocess.

In an embodiment, the pixel electrode 191 may alternatively be formed onthe layer of the color filter 230 or the layer of the first protectionfilm 181 without forming of the second protection film 182, and may havethree or more subpixel electrodes.

A lower-plate alignment film 291 is formed on the pixel electrode 191.The lower-plate alignment film 291 is substantially the same as that ofthe upper-plate alignment film 292, so a description thereof will beomitted for convenience of description.

The spacer 250 for maintaining a pair of display panels 100 and 200 at apredetermined distance, e.g., a cell gap, and the liquid crystal layer 3are formed between the lower and upper display panels 100 and 200. Theliquid crystals constituting the liquid crystal layer 3 may have arefractive index of, for example, about 1.3 to about 1.6. For example,in an embodiment, the liquid crystals constituting the liquid crystallayer 3 may have a refractive index of, for example, about 1.48.

To improve the transmittance of the liquid crystal display device, whenthe color filter 230 is formed on the lower display panel 100, the totalthickness of the silicon nitride (SiN x) formed in the pixel electrodearea of the lower display panel 100 may be, for example, about 3500 Å toabout 4000 Å, and when the color filter 230 is formed on the upperdisplay panel 200, the total thickness of the silicon nitride (SiNx)formed in the pixel electrode area of the lower display panel 100 maybe, for example, about 4000 Å to about 5000 Å. The total thickness ofthe silicon nitride (SiNx) is a sum of the thicknesses of the siliconnitrides (SiNx) constituting the gate insulating layer and theprotection films.

For example, in an exemplary embodiment of the present invention, thelower substrate, the gate insulating layer made of silicon nitrides(SiNx), the first protection film made of silicon nitrides (SiNx), thesecond protection film made of an organic insulating material ororganic/inorganic insulating material, and the pixel electrode made ofIZO or ITO may have a refractive index of about 1.5, about 1.9, about1.9, about 1.65 to about 1.9, and about 1.9, respectively, and theliquid crystal display device having these elements may increase itstransmittance by, for example, about 2% compared with the conventionalliquid crystal display device. An average refractive index of the liquidcrystal molecules may be, for example, 1.7 or more.

For example, in an embodiment of the present invention, the lowersubstrate, the gate insulating layer made of an organic insulatingmaterial or organic/inorganic insulating material, the first protectionfilm made of an organic insulating material or organic/inorganicinsulating material, and the pixel electrode made of IZO and ITO mayhave a refractive index of about 1.5, about 1.55, about 1.55 to about1.9, and about 1.9, respectively, and the liquid crystal display devicehaving these elements may improve its transmittance by about 4% comparedwith the conventional liquid crystal display device.

Shapes of the pixel electrode 191 according to an exemplary embodimentof the present invention will be described in detail below withreference to FIGS. 3, 5A, 5B, 16A to 16G, and 17A to 17G. FIG. 5A is anenlarged plan view of the central part A5 of the second subpixelelectrode 191 l shown in FIG. 3. FIGS. 5B and 17A to 17G are enlargedplan views illustrating other examples of the subpixel electrode shownin FIG. 5A. FIGS. 16A to 16G illustrate basic shapes of the microbranches 197 and the micro slits 199.

To increase the side visibility and brightness of the liquid crystaldisplay device, various parameters should be considered, such as, forexample, outer shapes of the pixel electrode 191 and the subpixelelectrodes 191 h and 191 l formed in each pixel region PX, an area ratioof subpixel electrodes, a shape of the pixel electrode, width anddistribution of the micro branches 197 and micro slits 199, and adirection of the micro branches 197. The figures presented below areillustrative, and may be subject to change according to the factors suchas a cell gap of the liquid crystal layer 3, a type of liquid crystal,and characteristics of an alignment film.

Outer Shapes of Pixel Electrode and Subpixel Electrodes

The pixel electrode 191 is separated into, for example, the first andsecond subpixel electrodes 191 h and 191 l. The separated first andsecond subpixel electrodes 191 h and 191 l have, for example, first andsecond liquid crystal capacitors Clch and Clcl, respectively, and thefirst and second liquid crystal capacitors Clch and Clcl may havedifferent sizes. The pixel electrode 191 and its subpixel electrodes 191h and 191 l have, for example, square outer shapes. In an embodiment,the pixel electrode 191 and its subpixel electrodes 191 h and 191 l mayhave, for example, zigzag, radial or diamond outer shapes. Exemplaryembodiments of the present invention are not limited to the above shapesbut rather the pixel electrode 191 and its subpixel electrodes 191 h and191 l may have various shapes. The first and second subpixel electrodes191 h and 191 l are, for example, spaced apart from each other in thevertical direction and are spaced apart from the gate line 121, therebyreducing the unnecessary parasitic capacitive coupling and decreasing akickback voltage Vkb. In an embodiment, the pixel PX may alternativelyinclude three or more subpixels. In an embodiment, the first subpixelelectrode 191 h may alternatively be substantially surrounded by thesecond subpixel electrode 191 l.

Area Ratio of Subpixel Electrodes

To increase the side visibility of the liquid crystal display device andto reduce the brightness loss thereof, the area of the second subpixelelectrode 191 l should be, for example, about 1 to 3 times the area ofthe first subpixel electrode 191 h. For example, in an embodiment, thearea of the second subpixel electrode 191 l is about 1.5 to 2 times thearea of the first subpixel electrode 191 h. The area of the secondsubpixel 190 l shown in FIG. 3 is about 1.75 times the area of the firstsubpixel 190 h. The side visibility refers to the visibility of theliquid crystal display device, which is determined according to theviewing angle at a side. As the quality of an image viewed at a side iscloser to the quality of an image viewed in the front, the sidevisibility is better.

Shape of Pixel Electrode

Referring to FIG. 3, the first and second subpixel electrodes 191 h and191 l have, for example, the cross-shaped branch portions 195 h and 195l, respectively, and each of the subpixel electrodes 191 h and 191 l hasfour domains divided by the cross-shaped branch portions 195 h and 195l. Each domain has, for example, multiple micro branches 197 h and 197 lthat obliquely extend outwardly from the cross-shaped branch portions195 h and 195 l. Referring to FIGS. 5A and 5B, the micro branches 197 hand 197 l have, for example, a linear or zigzag shape. The micro slits199 h and 199 l existing between the neighboring micro branches 197 hand 197 l are alternately arranged with respect to the micro branches197 h and 197 l. Each of the micro branches 197 h and 197 l may beformed symmetrically with respect to at least one selected from ahorizontal branch portion 195 a and a vertical branch portion 195 v ofthe cross-shaped branch portions 195 h and 195 l. In an embodiment, eachof the micro branches 197 h and 197 l may alternatively be formed in aportion where the horizontal branch portion 195 a and the verticalbranch portion 195 v of the cross-shaped branch portion meet each other,so as to move, for example, about 2 μm to about 5 μm from the positionwhere at least one of the horizontal branch portion 195 a and thevertical branch portion 195 v crosses the other branch portion, and aconcave or convex bend may be formed on the horizontal or verticalbranch portion 195 a or 195 v of the cross-shaped branch portion.Because of the shape of each of the micro branches 197 h and 197 lmoving away from the position where the horizontal and vertical branchportions 195 a and 195 v cross each other, and of the bend formed on thehorizontal or vertical branch portion 195 a or 195 v, an arrangement ofliquid crystal molecules formed in each of the domains does notinterfere with arrangements of liquid crystal molecules in otherdomains, reducing textures in the pixel regions.

FIG. 5A is an enlarged view of the central part A5 of the secondsubpixel electrode shown in FIG. 3. Stripe-shaped micro branches 197 andmicro slits 199 are shown. In the central part A5 of the second subpixelelectrode, the micro branches have a width S and the micro slits have awidth W as shown in the drawing. The micro slits 199 and the microbranches 197 are alternately arranged. In other words, the micro slits199 are interposed between the micro branches 197. The widths W of themicro slits 199 are gradually changed. A detailed description thereofwill be given below.

Zigzag-shaped micro branches 197 and micro slits 199 will be describedbelow with reference to FIG. 5B. Because the micro branches 197 h and197 l and the micro slits 199 h and 199 l are substantially the same inshape, the shape of only the micro branches 197 h and 197 l will bedescribed in detail for convenience of description. To prevent theexternal light applied the liquid crystal display device from beingreflected on the pixel electrode 191 causing occurrence ofrainbow-colored stains, the pixel electrodes 191 may be formed to havethe micro branches 197 formed in the shape of, for example, zigzag asshown in FIG. 5B. The zigzag shape may have repetitive and periodicpeaks and valleys.

The reason why the rainbow stains occur in the liquid crystal displaydevice will be described in brief below. The visible light applied tothe liquid crystal display device is diffracted by elements (e.g., microbranches) serving as diffraction gratings in the liquid crystal displaydevice, and then the liquid crystal display device may output reflectedlight by the diffracted light. Because the visible light includesdifferent wavelengths, the diffracted reflected light may havediffraction patterns with different diffraction angles. Therefore, whenthe fluorescent light is input to the liquid crystal display device, thediffraction patterns may have rainbow colors, so rainbow stains may beviewed in the liquid crystal display device. The diffraction of thevisible light may occur mainly by the difference in refractive indexbetween the materials upon which the visible light is incident, and thestructure of the pixel electrodes serving as the diffraction gratings.Accordingly, it was discovered by the inventors that if the differencein refractive index among the pixel electrodes, liquid crystals,alignment films, and insulating materials constituting the liquidcrystal display device is reduced, the diffraction of the visible lightmay be reduced, contributing to a reduction in the rainbow stain. Inaddition, it was discovered by the inventors that if the structure ofthe pixel electrodes serving as the diffraction gratings is adjusted,the diffraction of the visible light is scattered, contributing to areduction in the rainbow stain.

Therefore, to prevent the micro branch electrodes from serving asdiffraction gratings, the pixel electrodes should be formed as randomlyas possible. To make the pixel electrode's structure random, the microbranch electrodes should be formed to have random directions, widths,periods, shapes, gaps, etc. The micro branch electrodes may be formed tohave, for example, two or more directions in each domain, or to havedifferent directions among different domains. The micro branchelectrodes may be formed such that their widths may be gradually changedto be different from the widths of adjacent micro branch electrodes. Themicro branch electrodes may be periodically arranged such that in onedomain, multiple micro branch electrodes having a predetermined periodof width may be formed in one group and multiple groups having differentperiods may be formed. Referring to FIGS. 5A, 5B and 16A to 16G, themicro branches 197 or the micro slits 199 may have shapes of, forexample, stripes, bats, zigzags, multi-broken zigzags, waves, entases,paired entases, combined entases A, or combined entases B. Each of theshapes shown in FIGS. 16A to 16G may be a basic unit of the microbranches 197 or the micro slits 199 having a cyclic form, and is a shapeof the basic unit pixel electrode. The micro branches 197 or the microslits 199 may be formed by each or a combination of the shapes of thebasic unit pixel electrodes. The shapes of the basic unit pixelelectrodes may have a basic unit length of, for example, about 4 μm toabout 25 μm, and may have a width of about 1.5 μm or more. FIG. 16Aillustrates multi-broken zigzag shapes broken at angles of θba1 andθba2. The angles of θba1 and θba2 may be different from each other. FIG.16B illustrates wave shapes bent at an angle of θbb. FIG. 16Cillustrates entasis shapes whose central portion is smaller in thicknessthan both end portions. The entasis shapes may be applied to the microbranches 197 or the micro slits 199. FIG. 16D illustrates paired entasisshapes, which include pairs of a shape consisting of a straight linebent at an angle of θbd1 and θbd2 and a non-bent straight line and itssymmetrical shape. In an embodiment of the present invention, the anglesof θbd1 and θbd2 may instead be different from each other. FIG. 16Eillustrates shapes of combined entases A, a basic unit of which has ashape in which diamonds are connected between two bent straight lines inthe paired entasis shapes. FIG. 16F illustrates shapes of combinedentases B, in which diamonds are connected between two non-bent straightlines in the paired entasis shapes. FIG. 16G illustrates bat shapesconsisting of stripes having different widths at different portions. Thebat shapes may be stripe shapes in which two or more widths, e.g.,widths of about 1.8 μm, about 3.2 μm and about 4.5 μm, are repeatedlyconnected. The stripe-shaped basic unit pixel electrodes have alreadybeen described with reference to FIG. 5A, and the zigzag-shaped basicunit pixel electrodes will be described below with reference to FIG. 5B.In accordance with an exemplary embodiment of the present invention,micro branches 197 or micro slits 199 may be constructed by each or acombination of the shapes of basic unit pixel electrodes. In addition,micro branches 197 or micro slits 199 may be constructed, in which basicunits with different lengths are combined by each or a combination ofthe shapes of basic unit pixel electrodes. In the following description,the pixel electrodes are formed using the shapes of the basic unit pixelelectrodes.

In accordance with an exemplary embodiment of the present invention, themicro branch electrodes formed in the shapes of basic unit pixelelectrodes may be different in gaps from adjacent micro branchelectrodes.

Since a lot of a external visible light is incident if the color filter230 is formed on the lower display panel 100, the color filter 230 maybe formed on the upper display panel 200 to reduce the incidence of theexternal visible light.

The micro branches 197 l formed in a zigzag shape to reduce the rainbowstains will now be described in brief with reference to FIG. 5B. Thezigzag-shaped micro branches 197 l are constructed to have a zigzag unitlength P5 and a zigzag angle θ5. As to the zigzag unit length P5, eachof the micro branches 197 h and 197 l has a straight length, which is,for example, about 3 μm to about 25 μm. In an embodiment, each of themicro branches 197 h and 197 l has a straight length, which is, forexample, about 4 μm to about 10 μm. The main direction of the microbranches 197 formed in each domain is the direction in which a straightline connecting peaks PK1 and PK2 shown in FIG. 5B extends. The peaksPK1 and PK2 are adjacent points in one period in one micro branch 197.The zigzag angle θ5 is a bending angle between the main-direction lineof the micro branch 197 and the line corresponding to the zigzag unitlength P5, and the zigzag angle θ5 is, for example, about 0° to about±40°. In an embodiment, the zigzag angle θ5 is, for example, about ±12°to about ±20°. The diffraction light being diffracted by a pixelelectrode having a large zigzag angle θ5 or various zigzag angles θ5 isdispersed, contributing to a reduction in rainbow stains on the liquidcrystal display device. The zigzag-shaped micro branches 197 l extendfrom the vicinity of the horizontal branch portion 195 a and thevertical branch portion 195 v of the cross-shaped branch portion up tothe edge of each of the subpixel electrodes 191 h and 191 l. An increasein the number of zigzag shapes constituting the micro branch 197 leadsto an increase in the number of diffraction spots of light beingdiffracted by the zigzag shapes, thereby facilitating a reduction inrainbow stains on the liquid crystal display device. As the lightreflected on the micro branches 197 l of the pixel electrode 191 differsin interference effect according to wavelength, the micro branches 197formed on the pixel electrodes 191 associated with the color filters ofthe primary colors may have different zigzag unit lengths P5 anddifferent zigzag angles θ5. In this manner, if the micro branches 197 lhaving different zigzag shapes are formed on the pixel electrode 191according to the pixels of the primary colors, the rainbow stains of theliquid crystal display device may be reduced.

In an embodiment, one micro branch 197 constituting the pixel electrode191 may alternatively have zigzag unit lengths P5 of different sizes. Asthe micro branch 197 formed in this way has a high irregularity, thediffraction light diffracted by the micro branch 197 is dispersed,leading to a reduction in rainbow stains on the liquid crystal displaydevice. In an embodiment, one micro branch 197 h or 197 l constitutingthe pixel electrode 191 may be constructed, for example, in a mixedshape of straight lines and zigzags. In an embodiment, mixed microbranch electrodes of straight line-shaped micro branches 197 h and 197 land zigzag-shaped micro branches 197 h and 197 l may be constructed inone domain.

Shapes of micro branches 197 and micro slits 199 according to anembodiment of the present invention will now be described with referenceto FIGS. 17A to 17G. As the micro branches 197 and micro slits 199 aresubstantially similar in shape, a detailed description of the shapeswill be focused on the shapes of the micro branches 197 for convenienceof description. Micro branches 197 and micro slits 199 shown in FIGS.17A, 17B, 17C and 17E have zigzag shapes. A width S of each of the microbranches 197 and a width W of each of the micro slits 199 have beendescribed above with reference to FIG. 3 or 5A.

In the plan view of a pixel electrode shown in FIG. 17A, micro branches197 or micro slits 199 gradually change in width according to anexemplary embodiment of the present invention. FIG. 17A is a plan viewof a pixel electrode including four domains Dga1, Dga2, Dga3, and Dga4.The four domains have micro branches 197 extending in differentdirections, and these domains are separated by a cross-shaped branch 195and connected to the cross-shaped branch 195. Structures (e.g., shapes,lengths, widths and/or directions) of the micro branches 197constituting each domain are symmetrical about a horizontal branchportion 195 a and a vertical branch portion 195 v of the cross-shapedbranch 195. Alternatively, the micro branches 197 constituting thedomains may have different structures according to the domains, forexample, they may be designed to be asymmetrical about the horizontalbranch portion 195 a and the vertical branch portion 195 v of thecross-shaped branch 195.

As illustrated, the domain Dga1 includes, for example, a plurality ofsubdomains Gga1˜Ggan including a plurality of micro branches 197 and aplurality of micro slits 199. The plurality of subdomains may bedistinguished from other subdomains by widths and zigzag angles of themicro branches 197 and micro slits 199, and main directions θdga1 andθdgan and zigzag unit lengths ZLa1 and ZLan of the subdomains. Inaccordance with an exemplary embodiment of the present invention, thesubdomains are distinguished by the widths of the micro branches 197 andmicro slits 199. In other words, micro branches 197 or micro slits 199constituting a first subdomain Gga1 may be the same in width, butdifferent in width from micro branches 197 or micro slits 199constituting an n-th subdomain Ggan. Micro branches 197 or micro slits199 in the other domains Dga2, Dga3, and Dga4 may be equal in structureto those in the domain Dga1.

In accordance with an exemplary embodiment of the present invention,widths S and W of micro branches 197 and micro slits 199 constitutingthe domains Dga1, Dga2, Dga3, and Dga4 may be, for example, about 2.0 μmto about 6 μm, and may gradually increase along the dotted arrows. Inthe start portion of a dotted arrow, e.g., in the first subdomain Gga1shown in the domain Dga1, widths Sga1 and Wga1 of micro branches 197 andmicro slits 199 may be, for example, about 2.5 μm, and in the endportion of the dotted arrow, e.g., in the n-th subdomain Ggan shown inthe domain Dga1, widths Sgan and Wgan of micro branches 197 and microslits 199 may be, for example, about 5 μm. In a subdomain correspondingto the central portion where the dotted arrow passes by, widths of microbranches 197 and micro slits 199 may fall within a range of, forexample, about 2.5 μm to about 5 μm. The widths of micro branches 197and micro slits 199 may gradually increase along the dotted arrow up to,for example, about 0.25 μm.

Lengths Pga1 and Pgan (not shown) of zigzag units constituting each ofdomains Dga1, Dga2, Dga3, and Dga4 and shown therein may be, forexample, about 5 μm to about 20 μm. The zigzag unit lengths maygradually increase in a direction away from the horizontal branchportion 195 a and the vertical branch portion 195 v of the cross-shapedbranch 195.

A main direction angle for a main direction θdga of micro branches 197or micro slits 199 constituting the domains Dga1, Dga2, Dga3, and Dga4may be, for example, about ±30° to about ±60° with respect to thedirection D1. For example, in an embodiment, the main direction anglefor a main direction θdga of micro branches 197 or micro slits 199constituting the domains Dga1, Dga2, Dga3, and Dga4 may be, for example,about ±40° to about ±50° with respect to a direction D1. The maindirection θdga1 of micro branches 197 is a direction of a straight lineconnecting peaks Pga1 and Pga2 of a micro branch, shown in the domainDga1. Zigzag angles θga1 and θgan shown in the domain Dga1 may be, forexample, about 0° to about ±40° with respect to the main direction ofmicro branches 197 or micro slits 199. For example, zigzag angles θga1and θgan shown in the domain Dga1 may be, for example, about 0° to about±30° with respect to the main direction of micro branches 197 or microslits 199. Absolute values of the zigzag angles shown in FIG. 17A maygradually increase along the dotted arrow by a value within a range off,for example, about 2° to about 5°. A first zigzag angle θga1 formed inthe first subdomain Gga1 may be, for example, about 0°, and an n-thzigzag angle θgan formed in the n-th subdomain Ggan may be, for example,about +30° or about −30°. A main direction of micro branches 197 ormicro slits 199 may be determined as described in connection with FIG.5B, e.g., determined by a direction of a straight line connecting peaksof a zigzag shape. The formed pixel electrode has an irregularstructure, contributing to a significant reduction in rainbow stains onthe liquid crystal display device.

In the following description of FIGS. 17B to 17G, the correspondingdescription which has already been made with reference to FIGS. 5A, 5Band 17A is omitted, and only the different features in FIGS. 17B to 17Gare described in detail. Referring to FIG. 17B, each of four domainsDgb1, Dgb2, Dgb3, and Dgb4 has a plurality of first to n-th subdomainsGgb1˜Ggbn. Micro branches 197 and micro slits 199 in the domains Dgb1,Dgb2, Dgb3, and Dgb4 are formed asymmetrically about a cross-shapedbranch 195.

In the plan view of a pixel electrode shown in FIG. 17B, widths of microbranches 197 and micro slits 199 have various periods according to anexemplary embodiment of the present invention. Micro branches 197 ormicro slits 199 forming the four domains Dgb1, Dgb2, Dgb3, and Dgb4 areformed asymmetrically about the cross-shaped branch 195. In a domainDgb2, a main direction angle θdgb of micro slits 199 or micro branches197, determined by connecting peaks of each micro slit 199 or microbranch 197, is, for example, about ±45°, and a zigzag angle θgb thereofmay be, for example, about ±7° to about ±20°. For example, the zigzagangle θgb may be about ±10° or about ±15°. The domains Dgb1, Dgb2, Dgb3,and Dgb4 have, for example, the same main direction angles and zigzagangles θgb of micro branches 197. Each of the subdomains Ggb1, andGgb2˜Ggbn includes a predetermined number of micro branches and microslits interposed therebetween. Micro subdomains SWgb2 including adjacentmicro branch-micro slit pairs may be formed in subdomains periodically.Widths Wgb1 and Sgb1 of micro slits and micro branches constitutingmicro branch-micro slit pairs may be, for example, about 3 μm.Therefore, widths of micro subdomains SWgb2 may be, for example, about 6μm. In an exemplary embodiment of the present invention, if each of thesubdomains has four micro branches 197 and four micro slits 199, a widthof each subdomain SWgb1 may be, for example, about 26 μm. Therefore, asillustrated in FIG. 17B, each of domains Dgb1, Dgb2, Dgb3, and Dgb4 hassubdomains Ggb1, and Ggb2˜Ggbn, which may have the same widths of microsubdomains. However, widths Sgb2 of micro branches between adjacentsubdomains in each domain may be different from widths of micro branchesin each subdomain. For example, widths of micro branches in eachsubdomain may be about 3 μm, while the widths Sgb2 of micro branches maybe about 5 μm. In conclusion, widths of micro branches 197 betweenadjacent subdomains in each domain are different from widths of microbranches 197 in each subdomain, and micro branches and micro slitsformed in domains are asymmetrical about the cross-shaped branch,increasing irregularity of the pixel electrode structure, dispersingdiffraction spots of the light diffracted thereby, and thus contributingto a significant reduction in rainbow stains on the liquid crystaldisplay device. The number of subdomains in each of the aforementioneddomains is subject to change according to the size of the pixelelectrode.

In the plan view of a pixel electrode shown in FIG. 17C, micro branches197 constituting domains have different main directions according to anexemplary embodiment of the present invention. The pixel electrodeincludes, for example, four domains Dgc1, Dgc2, Dgc3, and Dgc4. Thedomains Dgc1, Dgc2, Dgc3, and Dgc4 have different main directions θdgc1,θdgc2, θdgc3, and θdgc4 of micro branches 197, determined by connectingpeaks of each of the micro branches 197. Main direction angles of themain directions θdgc1, θdgc2, θdgc3, and θdgc4 of micro branches ormicro slits forming domains may be, for example, different from eachother within about 30° to about 60°. For example, main direction anglesfor the main directions θdgc1, θdgc2, θdgc3 and θdgc4 may be about 50°,about 41.3°, about 40°, and about 48.7°, respectively. In these maindirections of micro branches 197, zigzag angles θgc1, θgc2, θgc3, andθgc4 of micro branches 197 may fall within a range of, for example,about ±5° to about ±30°. For example, the zigzag angles θgc1, θgc2,θgc3, and θgc4 of micro branches 197 may be, for example, about ±10° toabout ±15°. In accordance with an exemplary embodiment of the presentinvention, zigzag angles of micro branches 197 formed in each domain maybe different from each other and may gradually increase along a specificdirection. A difference between zigzag angles of adjacent micro branches197 may be, for example, about 0.5° to about 5°. For example, thedifference between zigzag angles of adjacent micro branches 197 may beabout 2° to about 3°. In accordance with another exemplary embodiment ofthe present invention, zigzag angles of micro branches 197 formed in onedomain may be, for example, the same as those of micro branches formedin the same subdomain, and different from those of micro branches formedin other subdomains. A difference in zigzag angles between subdomainsmay be, for example, about 0.5° to about 5°. For example, a differencein zigzag angles between subdomains may be about 2° to about 3°. On theother hand, zigzag angles of micro branches 197 formed in one domain maybe, for example, different from those of micro branches formed in thesame subdomain, and symmetrical to those of micro branches formed inother subdomains. Symmetry between domains Dgc1, Dgc2, Dgc3, and Dgc4,symmetry between subdomains Ggc1, and Ggc2˜Ggcn, widths Sgc1, Sgc2, andWgc1 of micro branches 197 and micro slits 199 constituting subdomainsGgc1, and Ggc2˜Ggcn in each domain, and periodicity and widths SWgc1 ofsubdomains Ggc1, and Ggc2˜Ggcn are largely similar to those described inconnection with FIG. 17B. In this way, main directions and zigzag anglesof micro branches 197 in two different domains among the domains areformed different from each other, thereby increasing irregularity of thepixel electrode structure, dispersing diffraction spots of the lightdiffracted thereby, and thus contributing to a significant reduction inrainbow stains on the liquid crystal display device. Alternatively, forexample, main directions θdgc1, θdgc2, θdgc3, and θdgc4 of the domainsmay be symmetrically paired.

In the plan view of a pixel electrode shown in FIG. 17D, shapes of microbranches Sgd1, Sgd2, and Sgd3 and micro slits Wgd1, Wgd2, and Wgd3constituting subdomains Ggd1˜Ggdn are combined according to an exemplaryembodiment of the present invention. The pixel electrode includes, forexample, four domains Dgd1, Dgd2, Dgd3, and Dgd4. Each of the domainsDgd1, Dgd2, Dgd3, and Dgd4 includes, for example, subdomains Ggd1˜Ggdnwhich are periodically repeated. Each of the subdomains Ggd1˜Ggdnincludes, for example, a plurality of micro branches Sgd1, Sgd2, andSgd3, and micro slits Wgd1, Wgd2, and Wgd3. Micro branches 197 and microslits 199 have shapes similar to the above-described combined entases A(see FIG. 16E) or combined entases B (see FIG. 16F). The micro branches197 may be formed as Sgd1, Sgd2 and Sgd3. A micro branch Sgd1 has, forexample, a shape formed in a combination of a straight line and azigzag. A micro branch Sgd2 has, for example, a shape symmetrical to themicro branch Sgd1. A micro branch Sgd3 has, for example, a rhombus ordiamond-connected shape. The shapes of micro branches 197 may be appliedto micro slits 199. The micro slits 199 may be formed as Wgd1, Wgd2 andWgd3. A micro slit Wgd1 has, for example, a shape formed in acombination of two zigzags. A micro slit Wgd2 has, for example, a shapeformed by a straight line and a zigzag which is smaller than the zigzagsof the micro slit Wgd1. A micro slit Wgd3 has, for example, a shapesymmetrical to the micro slit Wgd2. For example, widths SWgd ofsubdomains may be about 10 μm to about 40 μm, and widths of microbranches Sgd1, Sgd2, and Sgd3, and micro slits Wgd1, Wgd2, and Wgd3 maybe about 2 μm to about 10 μm. The shapes of micro slits 199 may beapplied to the micro branches 197. Micro branches 197 and micro slits199 constituting four domains Dgd1, Dgd2, Dgd3, and Dgd4, and maindirections of the micro branches 197 may be formed, for example,symmetrically about a cross-shaped branch 195. Any one of the maindirections of micro branches 197 may be, for example, about 30° to about60°. For example, any one of the main directions of micro branches 197may be about 45°. While it has been described that micro slits and microbranches in domains are symmetrical about the cross-shaped branch 195 inaccordance with an exemplary embodiment of the present invention, themicro slits and micro branches in domains may be formed asymmetrically,and main directions of micro branches 197 in domains may also beasymmetrical. In this manner, micro branches 197 constituting subdomainsare diverse in shape and width, thereby increasing irregularity of thepixel electrode structure, dispersing diffraction spots of the lightdiffracted thereby, and thus contributing to a significant reduction inrainbow stains on the liquid crystal display device.

In the plan view of a pixel electrode shown in FIG. 17E, micro slits 199having two different directions are provided diagonally in each of fourdomains Dge1, Dge2, Dge3, and Dge4 according to an exemplary embodimentof the present invention. The pixel electrode includes, for example,four domains Dge1, Dge2, Dge3, and Dge4. Domain Dge1 includes, forexample, subdomains Gge1 and Gge2. Subdomain Gge1 has, for example,micro branches 197 and micro slits 199, whose widths are Sge1 and Wge1,respectively. Subdomain Gge2 has, for example, micro branches 197 andmicro slits 199, whose widths are Sge2 and Wge2, respectively. Forexample, in accordance with an exemplary embodiment of the presentinvention, the widths Sge1 and Sge2 of micro branches may be different,and the widths Wge1 and Wge2 of micro slits may also be different. Forexample, the width Sge2 of micro branches may be greater than the widthSge1 of micro branches, or the width Wge2 of micro slits may be greaterthan the width Wge1 of micro slits. In accordance with an exemplaryembodiment of the present invention, a sum of a micro branch's widthSge1 and its adjacent micro slit's width Wge1 formed in the subdomainGge1 may be different from a sum of a micro branch's width Sge2 and itsadjacent micro slit's width Wge2 formed in the subdomain Gge2. Forexample, a sum (e.g., about 5.4 μm to about 10 μm) of a micro branch'swidth Sge2 and a width Wge2 of its adjacent micro slit 199 formed in thesubdomain Gge2 may be greater than a sum (e.g., about 4 μm to about 8μm) of a micro branch's width Sge1 and a width Wge1 of its adjacentmicro slit 199 formed in the subdomain Gge1. Between the subdomains Gge1and Gge2 may be another subdomain in which widths of micro branches 197or micro slits 199 may gradually change. Subdomains Gge1 and Gge2 havemicro branches 197 having two directions θge1 and θge2 different fromtheir main direction θdge. In other words, subdomains each have a regionincluding micro branches 197 in a direction θge1 and another regionincluding micro branches 197 in a direction θge2. Angles between thedirections θge1 and θge2 of micro branches and a direction D1 may be anyvalue within a range of, for example, about 40° to about 50° and anyvalue within a range of, for example, about 30° to about 39°. Forexample, angles between the directions θge1 and θge2 of micro branchesand the direction D1 may be, for example, about 42° and about 37°,respectively. Main direction angles for main directions θdge of microbranches 197 may be any value within a range of, for example, about 30°to about 60°. For example, the main direction angle may be, for example,about 45°. As illustrated in the domain Dge2, a straight line Ieconnecting points at which micro branches 197 change from a directionθge1 to a direction θge2, may be, for example, an arc of an ellipse, ora straight line. The above-described structure of micro branches 197 mayalso be applied to a structure of micro slits 199. The structure formedin the domain Dge1 may also be applied to other domains Dge2, Dge3, andDge4, and the pixel electrode's structures formed in the domains may be,for example, symmetrical about a horizontal portion 195 a or a verticalportion 195 v of the cross-shaped branch 195. The pixel electrode formedin this manner may change the strength of an electric field within aliquid crystal layer, thereby increasing side visibility of the liquidcrystal display device. In addition, irregularity of the pixel electrodestructure increases, thereby dispersing diffraction spots of externallight and contributing to a noticeable decrease in rainbow stains on theliquid crystal display device.

In accordance with another exemplary embodiment of the presentinvention, micro branches 197 having a direction θge2 may be closer to adata wiring than micro branches 197 having a direction θge1, and anangle between a data line 171 and the direction θge2 may be greater thanan angle between the data line 171 and the direction θge1. Since themicro branches 197 close to the data line 171 and having the directionθge2 are more perpendicular to the data line 171 than the micro branches197 having the direction θge1, the major axes or principal axes ofliquid crystal molecules adjacent to the data line 171 are arranged moreperpendicularly to the data line 171 than those of liquid crystalmolecules adjacent to a cross-shaped branch. Therefore, the major axesor principal axes of liquid crystal molecules arranged approximatelyperpendicular to the data line 171 may increase side visibilityrepresenting visibility in a direction perpendicular to the data line171. In addition, the micro branches 197 having the direction θge1 arearranged more parallel to the data line 171 than the micro branches 197having the direction θge2, thereby increasing side visibilityrepresenting visibility in a direction parallel to the data line 171 dueto the micro branches 197 having the direction θge1. The pixel electrodehaving micro branches 197 arranged in two or more directions mayincrease side visibility of the liquid crystal display device.

Micro branches 197 and micro slits 199 shown in FIGS. 17F and 17G have,for example, stripe shapes. Widths S and W of micro branches 197 andmicro slits 199 have been described in conjunction with FIGS. 3 and 5A.In the plan view of a pixel electrode shown in FIG. 17F, widths of microslits 199 gradually increase as they go from a horizontal portion 195 aor a vertical portion 195 v of a cross-shaped branch 195 toward the edgeof the pixel electrode, e.g., toward a vertical connection portion 193or a horizontal connection portion 194, according to an exemplaryembodiment of the present invention. In other words, as micro slits 199extend to the edge of the pixel electrode, their widths graduallyincrease. The pixel electrode has, for example, four domains Dgf1, Dgf2,Dgf3, and Dgf4. Domain Dgf1 includes, for example, subdomains Ggf1 andGgf2. Subdomain Ggf1 has micro branches 197 and micro slits 199 havingmicro branch's width Sgf1 and micro slit's width Wgf1, respectively,which change along their extension direction. In addition, the subdomainGgf1 has, for example, micro slits 199 or micro branches 197 having maindirection angles θdgf1 and θdgf2. The main direction angle of microslits or micro branches means an angle between a straight lineconnecting central points of widths of micro slits or micro branches anda polarization axis of a polarizer, or a direction D1. Widths Wgf1 ofmicro slits 199 constituting the subdomain Ggf1 gradually increase asthey go from a horizontal portion 195 a or a vertical portion 195 v of across-shaped branch 195 toward the edge of the pixel electrode, e.g.,toward a vertical connection portion 193 or a horizontal connectionportion 194. Widths Sgf1 of micro branches 197 may be constant, or maygradually increase as they go from the horizontal portion 195 a or thevertical portion 195 v of the cross-shaped branch 195 toward the edge ofthe pixel electrode, or toward the vertical connection portion 193 orthe horizontal connection portion 194 of the pixel electrode.

In accordance with another exemplary embodiment of the presentinvention, the main directions θdgf1 and θdgf2 of micro slits 199, shownin the subdomain Ggf1, may be, for example, different from each other.In the subdomain Ggf1, main direction angles for main directions θdgf1of micro slits 199 adjacent to a subdomain Ggf2 may be, for example,smaller than main direction angles for main directions θdgf2 of othermicro slits 199 in the subdomain Ggf2, and the main direction angles ofmicro slits 199 may gradually increase from the main direction angleθdgf1 to the main direction angle θdgf2. In accordance with an exemplaryembodiment of the present invention, main direction angles for maindirections θdgf1 and θdgf2 of micro slits 199 may be, for example, about30° to about 55°. Main direction angles of micro branches 197 aresubstantially similar to the main direction angles of micro slits 199.Any one of main direction angles for main directions θdgf1 and θdgf2 ofmicro slits 199, shown in the subdomain Ggf1, may be, for example,greater than main direction angles of micro slits 199, shown in thesubdomain Ggf2. The subdomain Ggf2 has micro branches 197 and microslits 199 having micro branch's width Sgf2 and micro slit's width Wgf2,respectively, which are constant along their extension direction. Themicro branch's width Sgf2 and micro slit's width Wgf2 may be, forexample, substantially equal in values. On the other hand, the microbranch's width Sgf2 and micro slit's width Wgf2 may be, for example,different to adjust the strength of an electric field being applied to aliquid crystal layer. Main directions of micro slits 199 or microbranches 197, shown in the subdomain Ggf2, are, for example,substantially the same. For example, the pixel electrode structureformed in the domain Dgf1 may be applied to the other domains Dgf2,Dgf3, and Dgf4, and the structures of a pixel electrode, formed in thedomains, may be symmetrical about the horizontal portion 195 a or thevertical portion 195 v of the cross-shape branch 195. The pixelelectrode including the micro branches 197 and micro slits 199 formed inthis manner can adjust the strength of an electric field formed in aliquid crystal layer according to the subdomains, thereby increasingside visibility of the liquid crystal display device or significantlyreducing rainbow stains of the liquid crystal display device.

In the plan view of a pixel electrode shown in FIG. 17G, a plurality ofmicro branches 197 and a plurality of micro slits 199 have two or morediscontinuous widths according to an exemplary embodiment of the presentinvention. The pixel electrode shown in FIG. 17G includes, for example,four domains Dgg1, Dgg2, Dgg3, and Dgg4. A domain Dgg1 has, for example,micro branches 197 and micro slits 199 in a stair shape. In other words,the micro branches 197 and micro slits 199 have various discontinuouswidths. As illustrated in FIG. 17G, each micro branch 197 has widthsSgg1, Sgg2 and Sgg3, and the widths of each micro branch 197 maydiscontinuously increase in an order of widths Sgg1, Sgg2 and Sgg3 asthey go from a horizontal portion 195 a or a vertical portion 195 v of across-shaped branch 195 to the edge of the pixel electrode. Each of themicro branch widths Sgg1, Sgg2 and Sgg3 may have any value within, forexample, a range of about 2.0 μm to about 6 μm. In accordance with anexemplary embodiment of the present invention, micro branch widths Sgg1,Sgg2 and Sgg3 may be, for example, about 1.8 μm, about 3.2 μm and about4.5 μm, respectively. Micro slit widths adjacent to the micro branchwidths Sgg1, Sgg2 and Sgg3 may be Wgg1, Wgg2 and Wgg3, respectively. Themicro slit widths Wgg1, Wgg2 and Wgg3 may have any value within a rangeof, for example, about 2.0 μm to about 6 μm. In accordance with anexemplary embodiment of the present invention, the micro slit widthsWgg1, Wgg2 and Wgg3 may be, for example, about 4.5 μm, about 3.2 μm andabout 1.8 μm, respectively. In each of adjacent micro branch-micro slitpairs, a sum of a micro branch width and a micro slit width may have,for example, two or more values. In accordance with an exemplaryembodiment of the present invention, for at least one micro branch 197situated diagonally in the domains, micro branch widths Sgg1, Sgg2,Sgg3, Sgg2, and Sgg1 may, for example, discontinuously increase anddecrease as they extend from the central portion of the pixel electrode,or the horizontal portion 195 a or the vertical portion 195 v of thecross-shaped branch 195, to the edge of the pixel electrode. In anexemplary embodiment of the present invention, at least one micro branch197 may, for example, increase in discontinuous widths as it goes fromthe horizontal portion 195 a or vertical portion 195 v of thecross-shaped branch 195 to the central portion of the domain, and maydecrease in discontinuous widths as it goes from the central portion ofthe domain to a vertical connection portion 193 or a horizontalconnection portion 194 of the pixel electrode, or to the edge of thepixel electrode. Other micro branches 197 may, for example, increase indiscontinuous micro branch widths as they go from the horizontal portion195 a or vertical portion 195 v of the cross-shaped branch 195 to theedge of the pixel electrode, and the other remaining micro branches 197may decrease in discontinuous micro branch widths as they go from thehorizontal portion 195 a or vertical portion 195 v of the cross-shapedbranch 195 to the edge of the pixel electrode. Micro branches 197 in asubdomain Ggg1 of the domain Dgg1 may have the same micro branch widthSgg1. The subdomain Ggg1 may be formed in, for example, a portionadjacent to the vertical connection portion 193 or horizontal connectionportion 194 of the pixel electrode, or the edge of the pixel electrode.A main direction of each of the micro branches 197 or micro slits 199formed in the domain Dgg1 is, for example, a direction of a straightline connecting central points of widths of the micro branches 197 ormicro slits 199, and main directions of the micro branches or microslits are parallel to each other. The pixel electrode structure formedin the domain Dgg1 may also be applied to, for example, other domainsDgg2, Dgg3, and Dgg4, and pixel electrode structures formed in thedomains may be symmetrical about the horizontal portion 195 a orvertical portion 195 v of the cross-shaped branch 195. The pixelelectrode including the micro branches 197 and micro slits 199 formed inthis manner may tilt liquid crystal molecules in a liquid crystal layerat various angles, thereby increasing side visibility of the liquidcrystal display device or significantly reducing rainbow stains of theliquid crystal display device.

The pixel electrode according to an exemplary embodiment may have, forexample, at least one V-shaped notch. In other words, a V-shaped notchmay be, for example, engraved or embossed on an electrode with the microbranches 197 or the cross-shaped branch portions 195. If the notch isformed on the pixel electrode, a response speed of the liquid crystaldisplay may increase and the luminance thereof may increase.

Referring to FIG. 3, the first and second subpixel electrodes 191 h and191 l have the vertical connection portions 193 h and 193 l both on theleft and right, respectively. The vertical connection portions 193 h and193 l block parasitic capacitive coupling occurring between the dataline 171 and the subpixel electrodes 191 h and 191 l. Referring to FIGS.4B and 4C, in adjacent pixels, the vertical connection portions 193 h ofthe first subpixel electrode 191 h overlap the vertical portions 128 ofthe storage electrode line by OLL1 and OLR1, respectively. Each of OLL1and OLR1 may be a value selected from, for example, about 0.5 μm toabout 3 μm. In adjacent pixels, the vertical connection portions 193 lof the second subpixel electrode 191 l overlap the vertical portions 128of the storage electrode line by OLL2 and OLR2, respectively. OLL2 andOLR2 may be values selected from, for example, about 1 μm to about 3 μm,respectively. To reduce a change in capacitance of the second liquidcrystal capacitor Clcl formed on the second subpixel electrode 191 l,OLL2 and OLR2 may be, for example, greater than or equal to OLL1 andOLR1, respectively. The light blocking member 220 formed on the upperdisplay panel 200 overlaps the vertical portions 128 of the storageelectrode line formed in the portion of the first subpixel electrode 191h by OBL1 and OBR1, respectively. Each of OBL1 and OBR1 may be, forexample, about 0.5 μm to about 3 μm. In addition, the light blockingmember 220 formed on the upper display panel 200 overlaps the verticalportions 128 of the storage electrode line formed in the region of thesecond subpixel electrode 191 l by OBL2 and OBR2, respectively. Each ofOBL2 and OBR2 may be, for example, about 0.5 μm to about 3 μm. The lightleakage of the liquid crystal display device may be increased bymatching values of OBL1, OBR1, OBL2 and OBR2 with process conditions andthe cell gap.

Widths and Distributions of Micro Branches and Micro Slits

To increase the transmittance and side visibility of the liquid crystaldisplay device and reduce occurrence of rainbow stains, the widths S ofthe micro branches 197 and the widths W of the micro slits 199 (shown inFIG. 5A) may be determined in different ways according to the parameterssuch as, for example, the thickness of the liquid crystal layer 3, thetype of the liquid crystal molecules 31, the maximum data voltage, andthe voltage ratio and area ratio of the first subpixel electrode 191 hand the second subpixel electrode 191 l.

Each of the widths S of the micro branches 197 and the width W of themicro slits 199 according to an exemplary embodiment of the presentinvention is, for example, about 2 μm to about 6 μm. For example, eachof the widths S of the micro branches 197 and the width W of the microslits 199 may be, for example, about 2.5 μm to about 4 μm.Alternatively, for example, if micro branches 197 are greater than microslits 199 in area, an electric field between the pixel electrode and thecommon electrode may increase, contributing to an increase in responsespeed and transmittance of the liquid crystal display device. Therefore,the micro branch widths S may not be limited to what is shown in thefigures. Referring to FIG. 3, S and W are constant in the first subpixelelectrode 191 h, and respective domains of the second subpixel electrode191 l have first to third regions HA, LA and MA according to the S and Wand the distributions of the micro branches and micro slits. In thefirst region HA, the width S of the micro branches 197 and the width Wof the micro slits 199 are defined as S1 and W1, respectively, and S1and W1 are, for example, the same. In the second region LA, the width Sof the micro branches 197 and the width W of the micro slits 199 aredefined as S2 and W2, respectively, and W2 is, for example, greater thanS2. In the third region MA, the width S of the micro branches 197 andthe width W of the micro slits 199 are defined as S3 and W3,respectively, and, for example, S3 is constant but W3 gradually changes.In the third region MA, W3 gradually increases as it gets close to thesecond region LA from the first region HA. S and W of the first subpixelelectrode 191 h according to an exemplary embodiment are, for example,about 3 μm and about 3 μm, respectively. For example, S1 and W1, S2 andW2 and S3 and W3 of the second subpixel electrode 191 l are about 3 μmand about 3 μm, about 3 μm and about 4 μm, about 3 μm and about 3 μm toabout 4 μm, respectively. The step, by which the width W3 of the secondsubpixel electrode 199 l gradually changes, is, for example, about 0.15μm to about 0.5 μm. For example, the step, by which the width W3 of thesecond subpixel electrode 199 l gradually changes, may be about 0.2 μm.On the other hand, for example, each of S3 and W3 in the third region MAmay gradually change, and S2 and W2 in the second region LA may begreater than S1 and W1 in the first region HA, respectively. The area ofthe first region HA formed in each domain of the second subpixelelectrode 191 l is, for example, greater than the area of the secondregion LA. For example, in an exemplary embodiment of the presentinvention, of the area of the entire region in each domain, eachsubpixel, or each pixel, e.g., of the combined area of the HA region,the LA region and the MA region, the area of the first region HA isabout 50% to about 80%, and the combined area of the second region LAand the third region MA is about 20% to about 50%. For example, the areaof the first region HA may be about 60% to about 70% and the combinedarea the second region LA and the third region MA may be about 30% toabout 40%. The areas of the first to third regions HA, LA and MA mayhave, for example, different distributions (sizes) in each domain. Thefirst to third regions HA, LA and MA may be formed, for example,symmetrically about at least a selected one of the horizontal branchportion and the vertical branch portion of each of the cross-shapedbranch portions 195 h and 195 l. Alternatively, for example, the firstto third regions HA, LA and MA may be formed even in the first subpixelelectrode 191 h.

Directions of Micro Branches

Because the major axis of the liquid crystal molecules 31 is tilted in adirection parallel to the micro branches 197 h and 197 l by the electricfield formed in the liquid crystal layer 3, the liquid crystal displaydevice having the micro branches 197 h and 197 l extending in thedirection of about 45° with respect to the polarization axis of thepolarizer has the maximum transmittance. Therefore, depending on thedirections of the micro branches 197 h and 197 l of the subpixelelectrodes 191 h and 191 l, the luminance and side visibility of theliquid crystal display device may vary based on the change intransmittance of light passing through regions of the subpixels 190 hand 190 l.

In each domain, directions of the micro branches 197 and the micro slits199 may be, for example, about 0° to about 45° with respect to at leasta selected one of a first direction D1 and a second direction D2. Forexample, in each domain, the directions of the micro branches 197 andthe micro slits 199 may be about 30° to about 45°, with respect to atleast a selected one of a first direction D1 and a second direction D2The first direction D1 and the second direction D2 may be a direction ofa polarization axis of a polarizer attached to the lower display panel100 or the upper display panel 200. Referring to FIG. 3, the microbranches 197 are formed in directions of θ1 and θ2 with respect to thepolarization axis of the polarizer in the first subpixel electrode 191 hand the second subpixel electrode 191 l, respectively, and θ1 and θ2are, for example, about 40° and about 45°, respectively. In an exemplaryembodiment, the 01 can be, for example, different from θ2 by about 20°or less. Directions of the micro branches 197 h and 197 l may be, forexample, about 30° to about 45° with respect to the direction of thehorizontal portion 195 a or vertical portion 195 v of the cross-shapedbranch 195, or the gate line 121. The direction of the gate line 121 maybe, for example, a direction of a virtual line passing by between thefirst subpixel electrode 191 h and the second subpixel electrode 191 lconstituting the pixel electrode. In the case of the zigzag-shaped microbranches 197 having a period of peaks PK1 and PK2 shown in FIG. 5B, thedirection in which the line connecting the peaks PK1 and PK2 extends isthe main direction of the micro branches 197. The micro branches 197 hand 197 l may have different directions according to the domains, thepixels, or the subpixel electrodes 191 h and 191 l.

A liquid crystal display panel assembly 300 according to an exemplaryembodiment of the present invention will be described in detail belowwith reference to FIGS. 18 to 21B. The liquid crystal display panelassembly 300 has patterns of a pixel electrode layer shown in FIGS. 18to 21B according to exemplary embodiments of the present invention,thereby increasing visibility of the liquid crystal display device andreducing stains and defects thereof.

FIG. 18 illustrates a schematic layout of a unit pixel of a liquidcrystal display panel assembly 300 according to an exemplary embodimentof the present invention. FIG. 19A is an enlarged view of a central partA19 of the pixel layout shown in FIG. 18. FIGS. 20A to 20D illustratepatterns for major layers of the pixel structure shown in FIG. 18,according to an exemplary embodiment of the present invention. Forexample, FIG. 20A illustrates a pattern of a gate layer conductor, FIG.20B illustrates a pattern of a data layer conductor, and FIG. 20Cillustrates a pattern of a pixel electrode layer. FIG. 20D illustratesanother pattern of the pixel electrode layer shown in FIG. 18, accordingto an exemplary embodiment of the present invention. Therefore, thepatterns of the gate layer conductor, the data layer conductor and thepixel electrode layer shown in FIGS. 20A to 20D should be construed tobe the same as the corresponding layers shown in FIG. 18. FIGS. 21A and21B are cross-sectional views taken along lines 21 a-21 a′ and 21 b-21b′ of the pixel layout shown in FIG. 18. The cross-sectional views shownin FIGS. 21A and 21B further disclose patterns of several other layersnot shown in FIG. 18. As to the cross-sectional views of the liquidcrystal display panel assembly 300 shown in FIGS. 21A and 21B, crosssections along the directions 21 a′ and 21 b′ are cross sections thatare formed along the cutting-plane lines shown in FIG. 18 when the pixelelectrode of FIG. 18 is repeatedly arranged in the form of a matrixconsisting of rows and columns. The pixel structures shown in FIGS. 18to 21B are similar to those described in connection with FIGS. 3 to 4C,so duplicate descriptions of similar parts will be omitted. In addition,reference numerals of the pixel structure shown in FIG. 3 may be used inFIGS. 18, and 19A to 20D.

As described above, a liquid crystal display panel assembly 300includes, for example, a lower display panel 100, an upper display panel200, a liquid crystal layer 3 between these display panels, andpolarizers situated on an inner or outer side of the display panels 100and 200. A stacked structure of the lower display panel 100 and upperdisplay panel 200 of the liquid crystal display panel assembly 300 willbe described in detail below.

1) Stacked Structure

As illustrated in FIGS. 21A and 21B, an upper display panel 200 has astructure, for example, in which a light blocking member 220, anovercoat 225, a common electrode 270, a spacer 250 (not shown), and anupper-plate alignment film 292 (e.g., 34 and 36) are stacked on an uppersubstrate 210 in sequence. The light blocking member 220, the overcoat225, the common electrode 270, the spacer 250, and the upper-platealignment film 292 may be formed by the manufacturing methods andmaterials described in connection with, for example, FIGS. 4A to 4C. Thelight blocking member 220 may overlap a data line 171. The lightblocking member 220 may be, for example, equal to the data line 171 inwidth, or may be as wide as, for example, about 0.5 μm to about 2 μm. Inaccordance with an exemplary embodiment of the present invention,instead of being formed on the upper display panel 200, the lightblocking member 220 may be formed, for example, between a color filter230 and a second protection layer 182 on a lower display panel 100 asillustrated in FIGS. 22A and 22B. In accordance with an exemplaryembodiment of the present invention, the upper display panel 200 may nothave the overcoat 225 to simplify a manufacturing process thereof. Inaccordance with an exemplary embodiment of the present invention, toreduce the height of the spacer 250 and uniformize the cell gap, thespacer 250 may be formed on, for example, the upper display panel 200 orthe lower display panel 100 so as to overlap the light blocking member220, a TFT, an outgassing color filter hole 235, or an outgassing holecover 187.

The lower display panel 100 shown in FIGS. 18 to 21B may have, forexample, a structure in which a lower substrate 110, gate layerconductors 121, 123, 124 h, 124 l, 124 c, 125, 126, 127, and 128, a gateinsulating layer 140, semiconductors 154 h, 154 l, and 154 c, a linearohmic contact member 165, data layer conductors 171, 173 h, 173 l, 173c, 175 h, 175 l, 175 c, and 177 c, a first protection layer 181, a colorfilter 230, a second protection layer 182, pixel electrode layers 187,189, 191 h, 191 l, 192 h, 192 l, 193 h, 193 l, 194 h, 194 l, 195 h, 195l, 196, 197 h, 197 l, 198 h, 198 l, 713 h, 713 l, 715 h, 715 l (notshown), 717 h, and 717 l, and a lower-plate alignment film 291 (e.g., 33and 35) are stacked in sequence. These elements may be formed by themanufacturing methods and materials described in connection with, forexample, FIGS. 4A to 4C.

A gate layer conductor is formed and patterned on the lower substrate110. The gate layer conductor may include, for example, a plurality ofgate lines 121, a plurality of down gate lines 123, a plurality of gateelectrodes 124, a plurality of storage electrode lines 125, a pluralityof storage electrode line's extension portions 126, a plurality ofstorage electrode line's horizontal portions 127, and a plurality ofstorage electrode line's vertical portions 128. Components of the gatelayer conductor may be formed of, for example, the above-describedcorresponding materials. The gate insulating layer 140 is formed andpatterned on the gate layer conductor. The gate insulating layer 140 maybe formed of, for example, the above-described materials and in theabove-described structures corresponding thereto. The semiconductor 154is formed and patterned on the gate insulating layer 140. Thesemiconductor 154 has first, second and third semiconductors 154 h, 154l, and 154 c. The semiconductors 154 may be separated from each other onthe gate electrodes 124 as described above. The semiconductor 154 may beformed of, for example, the above-described materials and in theabove-described structures corresponding thereto. The linear ohmiccontact member 165 is formed and patterned on the semiconductor 154. Thelinear ohmic contact member 165 has first, second and third linear ohmiccontact members, which are formed under a first source electrode 173 h,a first drain electrode 175 h, a second source electrode 173 l, a seconddrain electrode 175 l, a third source electrode 173 c and a third drainelectrode 175 c, respectively. In an exemplary embodiment of the presentinvention, the linear ohmic contact member 165 may be formed under thedata line 171. The linear ohmic contact member 165 may be formed of, forexample, the above-described materials and in the above-describedstructures corresponding thereto. A data layer conductor is formed andpatterned on the linear ohmic contact member 165. The data layerconductor has one end portion 177 c of the third drain electrode 175 c,which overlaps the data line 171, the first source electrode 173 h, thesecond source electrode 173 l, the third source electrode 173 c, thefirst drain electrode 175 h, the second drain electrode 175 l, the thirddrain electrode 175 c, and the storage electrode line's extensionportion 126. These elements may be formed of, for example, theabove-described materials and in the above-described structurescorresponding thereto. First, second and third TFTs Qh, Ql, and Qc areformed in the above-described structure corresponding thereto andoperate in the above-described method to drive a pixel PX. The firstprotection layer 181 is formed and patterned on the data layerconductor. The first protection layer 181 may be formed of, for example,the above-described materials and in the above-described structures, andperforms the aforementioned functions corresponding thereto. The colorfilter 230 is formed and patterned on the first protection layer 181. Nocolor filter is formed in the outgassing color filter hole 235. Theoutgassing color filter hole 235 is a hole through which debris or gasescan be discharged, which have been generated in a process of forming acolor filter. The outgassing color filter hole 235 may be formed on thepattern of a TFT, a gate layer conductor, or a data layer conductor.After the color filter process is completed, the outgassing color filterhole 235 is covered by a material forming a protection layer or a pixelelectrode layer. The color filter 230 may be formed of, for example, theabove-described materials and in the above-described structurescorresponding thereto. The second protection layer 182 is formed andpatterned on the color filter 230 or the first protection layer 181. Thesecond protection layer 182 may be formed of, for example, theabove-described materials and in the above-described structurescorresponding thereto.

A pixel electrode layer is formed and patterned on the second protectionlayer 182. The pixel electrode layer may have, for example, first andsecond subpixel electrodes 191 h and 191 l, first and second subpixelelectrode contact portions 192 h and 192 l, vertical connection portions193 h and 193 l, horizontal connection portions 194 h and 194 l,cross-shaped branch portions 195 h and 195 l, micro branches 197 h and197 l, zigzag micro branches 198 h and 198 l, first and second pixelelectrode's horizontal connection portions 713 h and 713 l, first andsecond pixel electrode's vertical connection portions 715 h and 715 l,first and second pixel electrode's oblique connection portions 714 h and714 l, and first and second pixel electrode connection portion couplingpoints 717 h and 717 l, which are formed on first and second subpixels190 h and 190 l, respectively, and may also have an outgassing holecover 187, a shield common electrode 196, and a shield common electrodeconnection portion 189. Referring to FIGS. 18, 21A and 21B, the shieldcommon electrode 196 overlaps the data line 171. The shield commonelectrode 196 may prevent an upper-plate common voltage from beingdistorted by the voltage being applied to the data line 171, or mayreduce parasitic capacitive coupling occurring between the data line 171and the subpixel electrodes 191 h and 191 l. Shield common electrodesmay stay in an equipotential state by being connected to each other byshield common electrode connection portions 189. A width of the shieldcommon electrode 196 may be, for example, greater than a width of thedata line 171 by distances OSL3 and OSR3 from both edges of the dataline 171 in a first subpixel region, and may be, for example, greaterthan the width of the data line 171 by distances OSL4 and OSR4 from bothedges of the data line 171 in a second subpixel region. The distancesOSL3, OSR3, OSL4 and OSR4 may fall within a range of, for example, about0.5 μm to about 2 μm. The shield common electrode 196 may be spacedapart from edges of storage electrode line's vertical portions 128situated on the left and right sides of the data line 171 by distancesOCL3 and OCR3 in the first subpixel region, and may be spaced apart fromedges of storage electrode line's vertical portions 128 situated in theleft and right sides of the data line 171 by distances OCL4 and OCR4 inthe second subpixel region. The distances OCL3, OCR3, OCL4 and OCR4 mayfall within a range of, for example, about 0.5 μm to about 3 μm. Theshield common electrode 196 may be floated so as not to receive avoltage, or may receive a predetermined voltage. The predeterminedvoltage may be, for example, a common voltage, an upper-plate commonvoltage, or a voltage applied to a storage electrode line. The shieldcommon electrode 196 may overlap light blocking members 220 h(corresponding to 220 of 190 h) and 220 l (corresponding to 220 of 190l). The outgassing hole cover 187 may be formed to, for example,completely cover the outgassing color filter hole 235. The outgassinghole cover 187 prevents the gases generated in the color filter 230 orlower layers from being discharged via the outgassing color filter hole235. Other components constituting the pixel electrode layer, except astructure of the pixel electrode, are substantially similar to thosedescribed above, so a detailed description thereof is omitted. Thestructure of the pixel electrode is described in detail below. Thelower-plate alignment film 291 is formed on the pixel electrode layer.The lower-plate alignment film 291 may be formed of, for example, theabove/below-described materials and in the above/below-describedmethods, and may perform the above/below-described functionscorresponding thereto.

2) Structure of Pixel Electrode

A structure of a pixel electrode layer and a cross-sectional view of aperipheral portion of a data line 171 will be described in detail belowwith reference to FIGS. 18 to 21B. The first subpixel electrode 191 h isformed in a region of the first subpixel 190 h, and the second subpixelelectrode 191 l is formed in a region of the second subpixel 190 l.Cross-shaped branch portions 195 h and 195 l of the first and secondsubpixel electrodes 191 h and 191 l, and vertical and horizontalconnection portions 193 h, 194 h, 193 l, and 194 l surrounding thevertical and horizontal edges of the first and second subpixelelectrodes 191 h and 191 l will now be described in detail.

The vertical connection portions 193 h and 193 l of the pixel electrodewill be described in detail with reference to FIGS. 18, 20C, 21A and21B. In each of the first and second subpixel electrodes 191 h and 191l, the vertical connection portions connect end portions of microbranches 197, and isolate micro slits 199 with the pixel electroderemoved. The vertical connection portions 193 h and 193 l of the pixelelectrode, formed in this way, may reduce parasitic capacitive coupling.In the first subpixel electrode 191 h, the vertical connection portions193 h are spaced apart from storage electrode line's vertical portions128 by a distance OLL3 without overlapping the storage electrode line'svertical portions 128 on the left side of the data line 171, but overlapthe storage electrode line's vertical portions 128 by the distance OLR3on the right side of the data line 171. Values of OLL3 and OLR3 may fallwithin a range of, for example, about 0.5 μm to about 2 μm. Byasymmetrically forming the vertical connection portions 193 h about thedata line 171 in this manner, image degradation occurring due tomis-alignment with other layers may be reduced. The image degradationmay occur due to mis-alignment with other layers in a first subpixelregion rather than in a second subpixel region. Referring to FIG. 21B,in the second subpixel electrode 191 l, vertical connection portions 193l overlap the storage electrode line's vertical portions 128 by OLL4 andOLR4 on the left and right sides of the data line 171, respectively.OLL4 and OLR4 may fall within a range of, for example, about 0.5 μm toabout 2 μm.

Referring to FIGS. 18 and 19A, an upper end of the first subpixelelectrode 191 h and a lower end of the second subpixel electrode 191 lhave horizontal connection portions 194 h and 194 l, respectively. Thehorizontal connection portions 194 h and 194 l connect end portions ofmicro branches 197 of the pixel electrode, and isolate micro slits 199with the pixel electrode removed. The horizontal connection portions 194h and 194 l overlap the storage electrode line's horizontal portions127. As the horizontal connection portions 194 h are not formed on alower end of the first subpixel electrode 191 h, micro branches 197formed in this portion are not connected to each other, but micro slits199 are connected to each other. Micro branches 197 h situated on thelower end of the first subpixel electrode 191 h may overlap the storageelectrode line 125. Micro branches 197 situated on the lower end of thesecond subpixel electrode 191 l are connected to each other to havehorizontal connection portions 194 l, and micro slits 199 are notconnected to each other. On the other hand, micro branches 197 lsituated in the upper end of the second subpixel electrode 191 l mayoverlap a down gate line 123. The micro branches 197 and micro slits 199formed in this way may increase a response speed of the liquid crystaldisplay device and reduce textures. In the alternative, for example,micro branches 197 situated on the lower end of the first pixelelectrode 191 h may be connected to each other, and micro slits 199 maynot be connected to each other. Further, micro branches 197 on the upperend of the second subpixel electrode 191 l may be, for example, isolatedby micro slits 199, and the micro slits 199 may be connected to eachother.

As illustrated in FIGS. 18 and 20C, first and second subpixel electrodes191 h and 191 l each have, for example, four domains includingzigzag-shaped micro branches 198 h and 198 l. In other words, the firstsubpixel electrode 191 h has, for example, four domains D21h1, D21h2,D21h3 and D21h4, and the second subpixel electrode 191 l has fourdomains D21l1, D21l2, D21l3 and D21l4. The domains D21h1, D21h2, D21h3,D21h4, D21l1, D21l2, D21l3 and D21l4 have main directions θd21h1,θd21h2, θd21h3, θd21h4, θd21l1, θd21l2, θd21l3 and θd21l4 (not shown) ofmicro branches 197, respectively, defined by directions of straightlines connecting peaks of the micro branches 197. Main direction anglesof main directions of micro branches in the domains may fall within arange of, for example, about 30° to about 60° with respect to thedirection D1. Main directions of micro branches in domains facing across-shaped branch's vertical portion 195 v may be, for example,symmetrical about the cross-shaped branch's vertical portion 195 v. Maindirection angles of the main directions θd21l1, θd21l2, θd21l3 andθd21l4 of micro branches may be, for example, greater than maindirection angles of the main directions θd21h1, θd21h2, θd21h3 andθd21h4 of micro branches. In accordance with an exemplary embodiment ofthe present invention, main direction angles of the main directionsθd21h1, θd21h2, θd21h3, θd21h4, θd21l1, θd21l2, θd21l3 and θd21l4 ofmicro branches may be, for example, about 40.8°, about 40.8°, about39.2°, about 39.2°, about 42°, about 42°, about 41.3° and about 41.3°,respectively. In accordance with an exemplary embodiment of the presentinvention, micro branches 197 and micro slits 199 formed in the domainshave patterns which are, for example, symmetrical about the cross-shapedbranch's vertical portion 195 v. In the domains D21h1, D21h2, D21h3,D21h4, D21l1, D21l2, D21l3 and D21l4, zigzag angles θ21h1, θ21h2, θ21h3,θ21h4, θ21l1, θ21l2, θ21l3 and θ21l4 (not shown) of micro branches 197may fall within a range of, for example, about ±7° to about ±30°. Forexample, in the domains D21h1, D21h2, D21h3, D21h4, D21l1, D21l2, D21l3and D21l4, zigzag angles θ21h1, θ21h2, θ21l13, θ21h4, θ21l1, θ21l2,θ21l3 and θ21l4 of micro branches 197 may fall within a range of about±10° or about ±15°. Zigzag angles of micro branches 197 formed indomains of the second subpixel electrode 191 l may be, for example,greater than zigzag angles of micro branches 197 formed in domains ofthe first subpixel electrode 191 h. In accordance with an exemplaryembodiment of the present invention, values of θ21h1, θ21h2, θ21h3 andθ21h4 may be, for example, about 10°, while values of θ21l1, θ21l2,θ21l3 and θ21l4 may be, for example, about 15°. It should be noted thatas described above, the zigzag angles of micro branches 197 mean anglesbetween main directions of micro branches 197 and zigzag directionsthereof.

The micro branches 197 and micro slits 199 of a pixel electrode shown inFIGS. 18 and 20C have, for example, zigzag shapes. Zigzag unit lengthsformed in the pixel electrode may fall within a range of, for example,about 5 μm to about 20 μm. In accordance with an exemplary embodiment ofthe present invention, zigzag unit lengths formed in the first andsecond subpixel electrodes 191 h and 191 l may be, for example, about 14μm and about 10 μm, respectively. Widths of micro branches 197 and microslits 199 formed in the domains of the pixel electrode may fall within arange of, for example, about 2 μm to about 5 μm. Widths of microbranches 197 and micro slits 199 included in domains may be, forexample, different according to the domains. Widths of micro branches197 h and micro slits 199 h in the domains D21h1, D21h2, D21h3 and D21h4may fall within a range of, for example, about 2.8 μm to about 3.7 μm,and widths of micro branches 197 and micro slits 199 may graduallyincrease along the arrows shown in the domains. In accordance with anexemplary embodiment of the present invention, widths of micro branches197 and micro slits 199 may be, for example, about 2.8 μm in startportions of the arrows in the domains, while widths of micro branches197 and micro slits 199 may be, for example, about 3.3 μm in endportions of the arrows. In accordance with an exemplary embodiment ofthe present invention, widths of micro branches 197 and micro slits 199may be, for example, about 3.3 μm in start portions of the arrows in thedomains, while widths of micro branches 197 and micro slits 199 may be,for example, about 3.7 μm in end portions of the arrows. Widths of microbranches 197 l and micro slits 199 l included in the domains D21l1,D21l2, D21l3 and D21l4 may fall within a range of, for example, about2.8 μm to about 3.9 μm, and widths of micro branches 197 and micro slits199 may gradually increase along the arrows shown in the domains. Inaccordance with an exemplary embodiment of the present invention, widthsof micro branches 197 and micro slits 199 may be, for example, about 2.8μm in start portions of the arrows in the domains, while widths of microbranches 197 and micro slits 199 may be, for example, about 3.9 μm inend portions of the arrows. Widths of micro branches 197 and micro slits199 in the domains D21h1, D21h2, D21h3, D21h4, D21l1, D21l2, D21l3, andD21l4 may gradually increase by a value within a range of, for example,about 0.2 μm to about 1 μm.

A pixel electrode structure with a pixel electrode layer according toexemplary embodiments of the present invention will be described indetail below with reference to FIGS. 20D to 20J. Patterns of a pixelelectrode layer shown in FIGS. 20D to 20J are other examples of thepatterns of a pixel electrode layer shown in FIGS. 18 and 20C.Therefore, other layers except for the pixel electrode layer are similarto those described in FIGS. 18 to 20C, so a duplicate descriptionthereof will be omitted. Subpixel electrodes formed in first and secondsubpixels 190 h and 190 l shown in FIG. 20D have a structure in whichend portions of micro branches 197 adjacent to a data line 171 are notconnected to each other according to an exemplary embodiment of thepresent invention. In other words, subpixel electrodes formed in firstand second subpixels 190 h and 190 l shown in FIG. 20D may not have thevertical connection portions 193 h and 193 l of the pixel electrodeshown in FIG. 20C. By not having the vertical connection portions 193 hand 193 l, the subpixel electrodes may be spaced apart farther from thedata line 171, reducing textures occurring in the subpixel electrodesadjacent to the data line 171. In accordance with an exemplaryembodiment of the present invention, the distance from end portions ofmicro branches 197 adjacent to the data line 171 up to the data line 171adjacent thereto may be, for example, greater than or equal to widths ofmicro branches 197 or micro slits 199. As illustrated in regions A20d ofFIG. 20D, vertical ends of micro branches 197 further project in uppercorner regions of the second subpixel, compared with vertical ends oftheir lower micro branches 197. The micro branches 197 projecting in theupper corner regions A20d can reduce textures occurring in subpixelregions adjacent to the data line 171 by blocking an electric fieldoccurring in a peripheral portion. Micro branches 197 projecting in thecorners may be formed in corners of first or second subpixel 190 h or190 l.

The pixel electrode shown in FIG. 20D has, for example, two subpixelelectrodes 191 h and 191 l, each of which has four domains. A firstsubpixel electrode 191 h has, for example, fourth domains D20dh1,D20dh2, D20dh3, and D20dh4, and a second subpixel electrode 191 l hasfour domains D20dl1, D20dl2, D20dl3, and D20dl4. Micro branches 197 andmicro slits 199 are, for example, symmetrical about a cross-shapedbranch 195. Micro branches 197 and micro slits 199, whose widthsgradually change, are formed in regions MA20d formed in the four domainsof the second subpixel electrode 191 l. Micro branches 197 constitutingthe pixel electrode have, for example, a stripe shape. Widths of microbranches 197 and micro slits 199 formed in first and second subpixels190 h and 190 l may fall within a range of, for example, about 2 μm toabout 5 μm. For example, widths of micro branches 197 and micro slits199 formed in first and second subpixels 190 h and 190 l may fall withina range of about 2.5 μm to about 3.5 μm. When micro branches 197 andmicro slits 199 are in the shape of stripes, an electric field formed ina liquid crystal layer may be high in strength, thereby increasingtransmittance of the liquid crystal display device. When the entireregion of micro branches 197 distributed over the pixel electrode isgreater than the entire region of micro slits 199, for example, whenwidths of micro branches 197 are greater and when widths of micro slits199 are less, an electric field between the pixel electrode and thecommon electrode may be high in strength, thereby increasing a responsespeed of the liquid crystal display device and increasing transmittancethereof.

In accordance with an exemplary embodiment of the present invention,widths of micro branches 197 and micro slits 199 formed in the firstsubpixel 190 h shown in FIG. 20D may be, for example, about 2.6 μm andabout 2.4 μm, respectively. In addition, widths of micro branches 197and micro slits 199 formed in the second subpixel 190 l may be, forexample, about 2.8 μm and about 3.4 μm in regions LA20d, respectively,may fall within a range of about 2.6 μm to about 2.8 μm and a range ofabout 2.4 μm to about 3.4 μm in regions MA20d, respectively and may beabout 2.6 μm and about 2.4 μm in regions HA20d, respectively. In theregions MA20d, widths of micro branches 197 and micro slits 199 maygradually increase by, for example, about 0.25 μm, and may fall within arange of, for example, about 5 μm to about 10 μm. For example, in theregions MA20d, widths of micro branches 197 and micro slits 199 may fallwithin a range of about 6.2 μm to about 10 μm. In the region of thesecond subpixel 190 l, an area of a sum of the regions LA20d and MA20d,and an area of the region HA20d may be, for example, about 45% and about55%, respectively. For example, directions of micro branches 197 andmicro slits 199 formed in this manner may be about 40° with respect to apolarization axis of a polarizer in a first subpixel region, and about45° with respect to a polarization axis of a polarizer in a secondsubpixel region. An area ratio of the first subpixel region to thesecond subpixel region may be, for example, about 1:2. A sum of areas ofdomains D20dl1 and D20dl2 formed in the region of the second subpixel190 l may be, for example, greater than a sum of areas of domains D20dl3and D20dl4.

In accordance with an exemplary embodiment of the present invention,widths of micro branches 197 and micro slits 199 formed in the firstsubpixel 190 h shown in FIG. 20D may be, for example, about 2.6 μm andabout 3.1 μm, respectively. In addition, for example, widths of microbranches 197 and micro slits 199 formed in the second subpixel 190 l maybe about 2.8 μm and about 3.4 μm in regions LA20d, respectively, mayfall within a range of about 2.6 μm to about 2.8 μm and a range of about2.4 μm to about 3.4 μm in regions MA20d, respectively and may be about2.6 μm and about 2.4 μm in regions HA20d, respectively. Other elementsmay be formed as correspondingly done, for example, in exemplaryembodiments described above. If widths of micro branches 197 are large,transmittance of the liquid crystal display device may increase and aresponse speed thereof may increase. However, if widths of micro slits199 are small or about 0, it may not be easy to form a pre-tilt angle ofliquid crystal molecules. Thus, it may be required to appropriatelycombine widths of micro branches 197 and micro slits 199.

FIG. 20E is a plan view of a pixel electrode according to an exemplaryembodiment of the present invention. In accordance with an exemplaryembodiment of the present invention, a pixel electrode illustrated inFIG. 20E is divided into five regions according to structures of microbranches 197 and micro slits 199, and in one or more regions, microslits 199 gradually increase in width as they extend from a cross-shapedbranch to the edge of the pixel electrode. The pixel electrode formed inthis manner reduces a curvature of a luminance ratio curve of the liquidcrystal display device, thereby visibility of the liquid crystal displaydevice. The luminance ratio curve represents changes in luminance ratioof the vertical axis with respect to a gray level of the horizontal axisas described below with reference to FIGS. 13A and 13B.

Each of first and second subpixel electrodes 191 h and 191 l is dividedinto, for example, four domains by a cross-shaped branch. Micro branches197 and micro slits 199 formed in the domains may be symmetrical aboutthe cross-shaped branch. The subpixel electrodes have micro branches 197and micro slits 199 in, for example, a stripe shape. The first subpixelelectrode 191 h has, for example, two different regions PH1-20e andPH2-20e according to the distribution of widths of micro branches 197and micro slits 199. In the region PH1-20e, micro branches 197 and microslits 199 are, for example, substantially constant in width along theirextension direction, and their widths may fall within a range of about1.5 μm to about 4.5 μm. For example, in the region PH1-20e, microbranches 197 and micro slits 199 may have a width of about 3 μm. Maindirections of extension directions of micro branches 197 and micro slits199 may fall within a range of, for example, about 30° to about 45° or arange of about 135° to about 150° with respect to the direction D1 shownin FIG. 20E or the gate line 121. For example, main directions ofextension directions of micro branches 197 and micro slits 199 may fallwithin a range of about 38° or about 142° with respect to the directionD1 shown in FIG. 20E or the gate line 121. For example, in the regionPH2-20e, widths of micro branches 197 are uniform along the extensiondirection of micro branches 197, and widths of micro slits 199 graduallyincrease along the extension direction of micro slits 199 as they goaway from the cross-shaped branch or go from the center to the edge ofthe subpixel electrode. The central line of the subpixel electrode maybe a cross line separating the subpixel electrode into domains, forexample, a cross-shaped branch. Widths of micro branches 197 may fallwithin a range of, for example, about 1.5 μm to about 5 μm. For example,widths of micro branches 197 may fall within a range of about 2.5 μm toabout 3.5 μm. Extension directions of micro branches 197 and micro slits199 are, for example, similar to the extension directions of microbranches 197 and micro slits 199 of the region PH1-20e in a boundaryportion with the region PH2-20e, and main direction angles of theextension directions of micro branches 197 and micro slits 199 graduallyincrease as they go away from the boundary portion with the regionPH2-20e. The extension direction of micro branches or micro slits meansa direction of a straight line connecting central points of widths ofmicro branches or micro slits, and it should be noted that an anglebetween the straight light and the direction D1 is an extensiondirection angle (or main direction angle) of micro branches or microslits.

The second subpixel electrode 191 l has, for example, three differentregions PL1-20e, PL2-20e, and PL3-20e according to the distribution ofwidths of micro branches 197 and micro slits 199. In region PL1-20e,micro branches 197 are, for example, uniform in width along theirextension direction, and micro slits 199 l gradually increase in width Walong their extension directions as they go away from a cross-shapedbranch or go from the center to the edge of the subpixel electrode.Widths of micro branches 197 may fall within a range of, for example,about 1.5 μm to about 5 μm. Main direction angles of micro branches 197and micro slits 199, for example, gradually increase as they go from ahorizontal portion 195 a of the cross-shaped branch 195 to a boundaryportion with the region PL2-20e. For example, in region PL2-20e, microbranches 197 and micro slits 199 are substantially uniform in widthalong their extension direction, and their widths may fall within arange of about 1.5 μm to about 4.5 μm. For example, in region PL2-20e,widths of micro branches 197 and micro slits 199 may be about 3 μm. Maindirection angles of micro branches 197 and micro slits 199 may fallwithin a range of, for example, about 30° to about 45° or a range ofabout 135° to about 150° with respect to the direction D1 or a directionof the gate line 121. For example, main direction angles of microbranches 197 and micro slits 199 may be about 38° or about 142° withrespect to the direction D1 or a direction of the gate line 121. In aregion PL3-20e, micro branches 197 are, for example, constant in widthalong their extension direction, and micro slits 199 l graduallyincrease in width along their extension direction as they go away fromthe cross-shaped branch 195. For example, widths of micro branches 197may fall within a range of, about 1.5 μm to about 5 μm, and widths ofmicro slits 199 may be greater than or equal to widths of adjacent microbranches 197. Main direction angles of extension directions of microbranches 197 and micro slits 199 are, for example, similar to the maindirection angles of extension directions of micro branches 197 and microslits 199 of the region PL2-20e in a boundary portion with the regionPL2-20e, and gradually increase as they go away from a boundary portionwith the region PL2-20e. The maximum main direction angle of microbranches 197 and micro slits 199 in the region PL1-20e may be, forexample, less than or equal to the main direction angle in the regionPL2-20e, and the minimum main direction angle of micro branches 197 andmicro slits 199 in the region PL3-20e may be, for example, greater thanor equal to the main direction angle in the region PL2-20e. The maximumwidth of micro branches 197 in the regions PL1-20e and PL3-20e may be,for example, greater than or equal to widths of micro branches 197 inthe region PL2-20e. Widths of micro branches 197 may be, for example,substantially similar in the regions PL1-20e, PL2-20e and PL3-20e. Inthe pixel electrode structure formed in this manner, the pixel electrodeformed in the regions PH2-20e and PL3-20e may reduce luminance visibleat the side, and the pixel electrode formed in the regions PH1-20e andPL1-20e may increase luminance visible at the side, thereby resulting ina reduction in curvature of the luminance ratio curve. The reduction incurvature of the luminance ratio curve may decrease a change in visibleluminance with respect to each gray level, thereby increasing visibilityof the liquid crystal display device. The luminance ratio curverepresents changes in luminance ratio of the vertical axis with respectto a gray level of the horizontal axis as described with reference toFIGS. 13A and 13B.

FIG. 20F is a plan view of a pixel electrode according to an exemplaryembodiment of the present invention. In accordance with an exemplaryembodiment of the present invention, a pixel electrode shown in FIG. 20Fhas five different regions according to the structure of micro branches197 and micro slits 199, and in one or more regions, micro branches 197gradually increase in width as they go away from a cross-shaped branch195 or go from the central line to the edge of a subpixel electrode. Aliquid crystal display device with such a pixel electrode has thecharacteristics described in connection with FIG. 20E. To avoid theduplicate description, the two-subpixel electrode structures, the domainstructures, the shapes of micro branches 197 or micro slits 199, thewidths of micro branches 197 and micro slits 199, and the directions ofmicro branches 197 and micro slits 199, which have been described aboveor described with reference to FIG. 20E, will be omitted or done inbrief.

A first subpixel electrode 191 h has, for example, two different regionsPH1-20f and PH2-20f according to the distribution of widths of microbranches 197 and micro slits 199. In the region PH1-20f, widths of microslits 199 are, for example, substantially uniform along with extensiondirections of the micro slits 199, and widths of micro branches 197gradually increase along extension directions of the micro branches 197as they go away from the cross-shaped branch 195 or go from the centralline of the subpixel electrode to the edge of the subpixel electrode.Main direction angles of micro branches 197 and micro slits 199 in theregion PH1-20f, for example, gradually increase as they get closer to aboundary portion with a region PH2-20f. In the region PH2-20f, microbranches 197 and micro slits 199 are, for example, substantially uniformin width along their extension direction. In this region, main directionangles of micro branches 197 and micro slits 199 may fall within a rangeof, for example, about 30° to about 45° or a range of about 135° toabout 150° with respect to the direction D1 or the gate line 121. Forexample, main direction angles of micro branches 197 and micro slits 199may be about 38° or about 142° with respect to the direction D1 or thegate line 121. The maximum width of micro branches 197 in the regionPH1-20f may be, for example, greater than or equal to widths of microbranches 197 in the region PH2-20f. Widths of micro slits 199 in theregion PH1-20f and widths of micro slits 199 in the region PH2-20f maybe, for example, substantially similar.

A second subpixel electrode 191 l has three different regions PL1-20f,PL2-20f, and PL3-20f according to the distribution of widths of microbranches 197 and micro slits 199. In the region PL1-20f, widths of microslits 199 are, for example, constant along extension directions of themicro slits 199, and widths of micro branches 197 gradually increasealong extension directions of the micro branches 197 as they go awayfrom the cross-shaped branch 195 or go from the center to the edge ofthe subpixel electrode. Widths of micro branches 197 may be, forexample, greater than or equal to widths of their adjacent micro slits199. Main direction angles for directions of micro branches 197 andmicro slits 199 may, for example, gradually increase as they get closerto a boundary portion with the region PL2-20f. In the region PL2-20f,widths of micro branches 197 and micro slits 199 are, for example,substantially uniform along extension directions of micro branches 197and micro slits 199. Main direction angles of micro branches 197 andmicro slits 199 may fall within a range of, for example, about 30° toabout 45° or a range of about 135° to about 150° with respect to thedirection D1 or the direction of the gate line 121. For example, maindirection angles of micro branches 197 and micro slits 199 may be about38° or about 142° with respect to the direction D1 or the direction ofthe gate line 121. In the region PL3-20f, widths of micro slits 199 are,for example, constant along extension directions of the micro slits 199,and widths of micro branches 197 gradually increase along extensiondirections of the micro branches 197 as they go away from thecross-shaped branch 195. Micro branches 197 may be, for example, greaterthan or equal to their adjacent micro slits 199 in width. Main directionangles of micro branches 197 and micro slits 199 are, for example,similar to the main direction angles of micro branches 197 and microslits 199 formed in the region PL2-20f in a boundary portion with theregion PL2-20f, and gradually increase as they go away from the boundaryportion with the region PL2-20f. The maximum direction angle of microbranches 197 and micro slits 199 in the region PL1-20f may be, forexample, less than or equal to the main direction angles in the regionPL2-20f, and the minimum direction angles of micro branches 197 andmicro slits 199 in the region PL3-20f may be, for example, greater thanor equal to the main direction angles of micro branches 197 and microslits 199 in the region PL2-20f. The maximum width of micro branches 197in the regions PL1-20f and PL3-20f may be, for example, greater than orequal to the widths of micro branches 197 in the region PL2-20f. Widthsof micro slits 199 may be, for example, substantially similar in theregions PL1-20f, PL2-20f and PL3-20f. The pixel electrode formed in thismanner may increase side visibility of the liquid crystal display deviceas described above.

FIG. 20G is a plan view of a pixel electrode according to an exemplaryembodiment of the present invention. In accordance with an exemplaryembodiment of the present invention, a pixel electrode shown in FIG. 20Ghas four different regions according to the structure of micro branches197 and micro slits 199, and in each of the regions, micro branches 197or micro slits 199 are broken (e.g., bent) once. The micro branches 197formed in this manner generally do not reduce the strength of anelectric field formed in a liquid crystal layer, avoiding a reduction intransmittance of the liquid crystal display device and increasingvisibility of the liquid crystal display device. The features of thecurrent exemplary embodiment of the present invention will be describedin detail below; however, those features overlapping with theembodiments described above are omitted. Micro branches 197 and microslits 199 formed in regions of first and second subpixel electrodes 191h and 191 l have, for example, constant widths along their extensiondirections. Micro branches 197 in domains of the subpixel electrodes 191h and 191 l have, for example, a bifurcated stripe shape broken (e.g.,bent) once. Micro branches 197 with a bifurcated stripe shape extend,for example, in two different directions. Micro branches 197 of thefirst and second subpixel electrodes 191 h and 191 l include, forexample, micro branches 197 with a first stripe shape and micro branches197 with a second stripe shape. Micro branches 197 with the first stripeshape are micro branches 197 connected to a cross-shaped branch 195, andmicro branches 197 with the second stripe shape are micro branches 197connected to micro branches 197 with the first stripe shape. In thefirst subpixel electrode 191 h, direction angles of micro branches 197having the first stripe shape with respect to the direction D1 or adirection of the gate line 121 may fall within a range of, for example,about 30° to about 39° and direction angles of micro branches 197 havingthe second stripe shape with respect to the direction D1 or a directionof the gate line 121 may fall within a range of about 40° to about 50°.For example, n the first subpixel electrode 191 h, direction angles ofmicro branches 197 having the first stripe shape with respect to thedirection D1 or a direction of the gate line 121 may be about 37° anddirection angles of micro branches 197 having the second stripe shapewith respect to the direction D1 or a direction of the gate line 121 maybe about 42°. In the second subpixel electrode 191 l, direction anglesof micro branches 197 having the first stripe shape with respect to thedirection D1 or a direction of the gate line 121 may fall within a rangeof, for example, about 30° to about 39°, and direction angles of microbranches 197 in the second stripe shape with respect to the direction D1or a direction of the gate line 121 may fall within a range of about 40°to about 50°. For example, in the second subpixel electrode 191 l,direction angles of micro branches 197 having the first stripe shapewith respect to the direction D1 or a direction of the gate line 121 maybe about 37° and direction angles of micro branches 197 in the secondstripe shape with respect to the direction D1 or a direction of the gateline 121 may be about 42°.

The first subpixel electrode 191 h has, for example, two differentregions PH1-20g and PH2-20g according to the widths of micro branches197 and micro slits 199. In each of the regions PH1-20g and PH2-20g,widths of micro branches 197 and micro slits 199 are uniform. In theregion PH1-20g, micro branches 197 may be, for example, greater thanmicro slits 199 in width. In the region PH2-20g, widths of microbranches 197 are, for example, substantially equal to widths of microslits 199. Widths of micro branches 197 in the region PH1-20g may be,for example, greater than widths of micro branches 197 in the regionPH2-20g. Widths of micro slits 199 may be, for example, substantiallythe same in the regions PH1-20g and PH2-20g. The second subpixelelectrode 191 l has, for example, two different regions PL1-20g andPL2-20g according to the widths of micro branches 197 and micro slits199. In the region PL1-20g, micro slits 199 may be, for example, greaterthan micro branches 197 in width. In the region PL2-20g, widths of microbranches 197 are, for example, substantially equal to widths of microslits 199. Widths of micro slits 199 in the region PL1-20g may be, forexample, greater than widths of micro slits 199 in the region PL2-20g.Widths of micro branches 197 in the region PL1-20g may be, for example,substantially equal to widths of micro branches 197 in the regionPL2-20g. Widths of micro branches 197 in the region PL1-20g may be, forexample, greater than widths of micro branches 197 in the regionPL2-20g. The pixel electrode formed in this manner can increase sidevisibility of the liquid crystal display device without reducingtransmittance thereof.

FIG. 20H is a plan view of a pixel electrode according to an exemplaryembodiment of the present invention. A pixel electrode illustrated inFIG. 20H is substantially equal in structure to the pixel electrodedescribed in connection with FIG. 20E, except for micro branches 197having a zigzag shape and horizontal and vertical connection portions193 l and 194 l formed in a second subpixel electrode 191 l. Forsimplicity, the duplicate description will be omitted. Micro branches197 illustrated in FIG. 20H have a zigzag shape to reduce rainbow stainsof the liquid crystal display device as described above. The pixelelectrode has five different regions PH1-20h, PH2-20h, PL1-20h, PL2-20h,and PL3-20h according to the structures of micro branches 197 and microslits 199, and micro slits 199 gradually increase in width as they gofrom a cross-shaped branch 195 to the edge of the pixel electrode. Eachof the first and second subpixel electrodes 191 h and 191 l is dividedinto, for example, four domains by the cross-shaped branch 195. Widthsof micro branches 197 and micro slits 199, and main direction angles ofmicro branches 197 and micro slits 199 in regions PH1-20h, PH2-20h,PL1-20h, PL2-20h, and PL3-20h have been described with reference to FIG.20E. The pixel electrode formed in this manner can increase visibilityof the liquid crystal display device and reduce rainbow stains.

FIG. 20I is a plan view of a pixel electrode according to an exemplaryembodiment of the present invention. A pixel electrode illustrated inFIG. 20I is substantially equal in structure to the pixel electrodedescribed in conjunction with FIG. 20G, except for micro branches 197having a zigzag shape, horizontal and vertical connection portions 193 land 194 l formed in a second subpixel electrode 191 l, and widths ofmicro branches 197 and micro slits 199 formed in a region PL1-20i. Forsimplicity, the duplicate description will be omitted. Micro branches197 illustrated in FIG. 20I have, for example, a zigzag shape to reducerainbow stains of the liquid crystal display device as described above.In the region PL1-20i of the second subpixel electrode 191 l, widths ofmicro branches 197 may be, for example, greater than widths of microslits 199. In a region PL2-20i, widths of micro branches 197 are, forexample, substantially equal to widths of micro slits 199. Widths ofmicro branches 197 in the region PL1-20i may be, for example, greaterthan widths of micro branches 197 in the region PL2-20i. Widths of microslits 199 in the region PL1-20i may be, for example, substantially equalto widths of micro slits 199 in the region PL2-20i. The pixel electrodehas, for example, four different regions PH1-20i, PH2-20i, PL1-20i, andPL2-20i according to the structures of micro branches 197 and microslits 199. Micro branches 197 and micro slits 199 are, for example,constant in width along their extension directions, and each of firstand second subpixel electrodes 191 h and 191 l is, for example, dividedinto four domains by a cross-shaped branch 195. Except for widths ofmicro branches 197 and micro slits 199 formed in the region PL1-20i,widths of micro branches 197 and micro slits 199 in the regions PH1-20i,PH2-20i, and PL2-20i and main direction angles of micro branches 197 andmicro slits 199 in the regions PH1-20i, PH2-20i, PL1-20i, and PL2-20i,are, for example, similar to those described in conjunction with FIG.20G. The pixel electrode formed in this manner can increase visibilityof the liquid crystal display device and reduce rainbow stains.

FIG. 20J is a plan view of a pixel electrode according to an exemplaryembodiment of the present invention. A pixel electrode illustrated inFIG. 20J is, for example, substantially similar in structure to thepixel electrode described in connection with FIG. 3, except that thevertical connection portions 193 do not exist in a third region, or aregion MA20j. For simplicity, the duplicate description will be omitted.The region MA20j is similar to the region MA described in connectionwith FIG. 3, in which widths of micro branches 197 or micro slits 199gradually change. In the region MA, e.g., the MA-LA boundary region orthe MA-HA boundary region of the pixel electrode illustrated in FIG. 3,since widths of micro branches 197 or micro slits 199 change, thebalance between the strength of an electric field formed by verticalconnection portions 193 of the pixel electrode and the strength of anelectric field formed by micro branches 197 or micro slits 199 may bebroken. Due to the broken balance, in these regions, liquid crystalmolecules may be arranged irregularly, generating textures. To correctthis, the pixel electrode may not have the vertical connection portions193 in the region MA20j adjacent to the data line 171 as illustrated inFIG. 20J. In other words, in the region MA20j adjacent to the data line171, micro slits 199 are connected and ends of micro branches 197 may beclosed (or isolated). In the region MA20j where the vertical connectionportions 193 do not exist, which are formed in other regions HA20j andLA20j, an electric field formed by the vertical connection portions 193may not exist or is very weak. Therefore, in the region MA20j adjacentto the data line 171, as liquid crystal molecules may be significantlyinfluenced by the electric field formed by micro branches 197 or microslits 199, the liquid crystal molecules may be arranged in the directionof the micro branches 197. The pixel electrode formed in this manner canreduce textures in the region MA20j, and increase transmittance of theliquid crystal display device.

Structures of a liquid crystal display panel assembly 300 according toother exemplary embodiments of the present invention will be describedin detail below with reference to FIGS. 22A to 22H. Liquid crystaldisplay panel assemblies 300 illustrated in FIGS. 22A to 22H havedifferent stacked structures according to an exemplary embodiment of thepresent invention. These stacked structures may enable uniform formationof photo hardening layers 35 and 36 or reduce a non-hardened lighthardener in the below-described process for manufacturing liquid crystaldisplay panel assemblies of certain modes. Main alignment films 33 and34 and photo hardening layers 35 and 36 constituting alignment filmsincluded in the upper or lower display panel 200 or 100 are formed on aflat lower layer, thus increasing display quality of the liquid crystaldisplay device. FIGS. 22A to 22H are cross-sectional views taken alongline 21 a-21 a′ of the pixel layout shown in FIG. 18. The liquid crystaldisplay panel assemblies 300 illustrated in FIGS. 22A to 22H are similarto those described in connection with FIGS. 3 to 4C and 18 to 21B,except for the stacked structures. Thus, duplicate descriptions will beomitted. Therefore, the liquid crystal display panel assemblies 300having the structures of FIGS. 22A to 22H may have above/below-describedpatterns of a pixel electrode layer.

The liquid crystal display panel assemblies 300 illustrated in FIGS. 22Ato 22D have a light blocking member 220 formed on a lower display panel100. First, a method of manufacturing a liquid crystal display panelassembly 300 according to an exemplary embodiment of the presentinvention and a structure thereof will be described in brief withreference to FIG. 22A. An upper display panel 200 has, for example, anupper substrate 210, a common electrode 270 and an upper-plate alignmentfilm 292 (shown as 34 and 36). The common electrode 270 is formed on theupper substrate 210 by, for example, the above-described methodcorresponding thereto, and the upper-plate alignment film 292 is formedon the common electrode 270 by a corresponding technique to be describedbelow with regard to a liquid crystal display panel assembly of acertain mode. The upper-plate alignment film 292 may include, forexample, a main alignment film 34 and a photo hardening layer 36.

The lower display panel 100 is manufactured as described below. On alower substrate 110 is formed a gate layer conductor including storageelectrode line's vertical portions 128. The gate layer conductor mayhave, for example, the above-described patterns 121, 123, 124 h, 124 l,124 c, 125, 126, and 127. A gate insulating layer 140 is formed on thegate layer conductor. A semiconductor 154 is formed on the gateinsulating layer 140. The semiconductor 154 may have, for example, theabove-described patterns 154 h, 154 l, and 154 c. A linear ohmic contactmember 165 is formed on the semiconductor 154. The linear ohmic contactmember 165 may have, for example, the above-described patternscorresponding thereto. On the linear ohmic contact member 165 is formeda data layer conductor including a data line 171. The data layerconductor may have, for example, the above-described patterns 173 h, 173l, 173 c, 175 h, 175 l, 175 c, and 177 c. A first protection layer 181is formed on the data layer conductor. For example, the first protectionlayer 181 may be the above-described inorganic insulating material suchas, silicon nitride (SiNx), silicon oxide (SiOx), titanium oxide (TiO₂),alumina (Al₂O₃) or zirconia (ZrO₂). Color filters 230 are formed on thefirst protection layer 181. The color filters 230 may overlap, forexample, the data line 171, a storage electrode line adjacent to thedata line 171, or the light blocking member 220 formed on the colorfilters 230. As illustrated in FIG. 22A, for example, the light blockingmember 220 is formed to overlap at least sidewalls of the color filters230 overlapping the storage electrode line's vertical portions 128situated on both sides of the data line 171 interposed between twoadjacent unit pixels, and to overlap the data line 171 between thesidewalls. The color filters 230 may have, for example, red (R), green(G) and blue (B) components, or may have red, green, blue, and yellowcomponents. The light blocking member 220 is formed on the color filters230. The light blocking member 220 may, for example, completely coverthe data line 171, or may overlap vertical connection portions 193 hsituated on both sides of the data line 171. The light blocking member220 may be formed on, for example, a channel of a TFT. The lightblocking member 220 may not be formed, for example, under contact holes185 h and 185 l. A second protection layer 182 is formed on the lightblocking member 220. For example, the second protection layer 182 may bean inorganic insulating material such as silicon nitride (SiNx), siliconoxide (SiOx), titanium oxide (TiO₂), alumina (Al₂O₃) or zirconia (ZrO₂).A pixel electrode layer is formed on the second protection layer 182.The pixel electrode layer may have, for example, theabove/below-described patterns 187, 189, 191 h, 191 l, 192 h, 192 l, 193l, 194 h, 194 l, 195 h, 195 l, 196, 197 h, 197 l, 198 h, 198 l, 713 h,713 l, 715 h, 715 l, 717 h, and 717 l, including vertical connectionportions 193 h, and a pixel electrode structure. The vertical connectionportions 193 h formed on both sides of the data line 171 may, forexample, overlap at least one portion of the storage electrode line'svertical portions 128. A spacer 250 (not shown) is formed on the pixelelectrode layer. The spacer 250 may include, for example, a pigmentconstituting color filters, and may be made of a colored substance. Inaccordance with an exemplary embodiment of the present invention, thespacer 250 may have, for example, a black color. In accordance with anexemplary embodiment of the present invention, both a spacer 250 and alight blocking pattern may be formed in an inner region and an outerregion of the lower display panel 100, respectively. The spacer 250 andthe light blocking pattern may be, for example, black, and the lightblocking pattern may block light which is leaked in the outer region. Alower-plate alignment film 291 is disposed on the spacer 250 as will beexplained in at least one of the below-described modes of a liquidcrystal display panel assembly. The lower-plate alignment film 291 mayinclude, for example, a main alignment film 33 and a photo hardeninglayer 35. A liquid crystal layer 3 is formed between the upper and lowerdisplay panels 200 and 100. The lower display panel 100 manufactured inthis way includes, for example, an opaque film or the light blockingmember 220. In other words, on the lower display panel 100 are formedlayers blocking or absorbing light, for example, the protection layers181 and 182, the color filters 230, or the light blocking member 220.However, the upper display panel 200 does not generally includematerials blocking or absorbing light. As the upper display panel 200manufactured in this way has a lesser number of materials blocking orabsorbing light, the light incident upon the upper display panel 200 ina process for manufacturing a liquid crystal display panel assembly of acertain mode may be uniformly incident upon the materials forming thelower-plate alignment film 291 and the upper-plate alignment film 292.To form uniform lower-plate and upper-plate alignment films 291 and 292,the light which is irradiated in an electric-field or fluorescentlithography process may be, for example, uniformly irradiated to thematerials forming alignment films. To reduce a non-hardened lighthardener, there may be no region to which light is not irradiated. Bydoing so, the lower-plate and upper-plate alignment films 291 and 292are uniformly formed, and the non-hardened light hardener may besignificantly reduced. Because the upper display panel 200 has mostlyflat layers, liquid crystal molecules may be uniformly aligned, therebyincreasing the display quality of the liquid crystal display device.

A method of manufacturing a liquid crystal display panel assembly 300according to an exemplary embodiment of the present invention and astructure thereof will be described below in brief with reference toFIG. 22B. A liquid crystal display panel assembly 300 illustrated inFIG. 22B is manufactured by a process in which a light blocking member220 and a spacer (not shown) are simultaneously formed on a pixelelectrode layer according to an exemplary embodiment of the presentinvention. An upper display panel 200 is manufactured as described withreference to FIG. 22A. A lower display panel 100 is manufactured asdescribed below. A gate layer conductor, a gate insulating layer 140, asemiconductor 154, a linear ohmic contact member 165, a data layerconductor, a first protection layer 181 and color filters 230 are formedas described with reference to FIG. 22A. A second protection layer 182is formed on the color filters 230. For example, the second protectionlayer 182 may be made of an organic insulating material to planarize theupside of the color filters 230. A pixel electrode layer is formed onthe second protection layer 182. The pixel electrode layer may beformed, for example, as described with reference to FIG. 22A. A lightblocking member 220 and a spacer 250 are, for example, simultaneouslyformed on the pixel electrode layer. As the light blocking member 220and the spacer 250 are simultaneously formed of the same material, theprocess may be simplified. The spacer 250 may be colored, for example,as described above with reference to FIG. 22A. In accordance with anexemplary embodiment of the present invention, the light blocking member220 and the spacer 250 may be, for example, black. A lower-platealignment film 291 (shown as 33 and 35) is formed on the spacer 250 (notshown) by the below-described methods. The lower and upper displaypanels 100 and 200 formed in this way may have, for example, thecharacteristics described with reference to FIG. 22A.

A method of manufacturing a liquid crystal display panel assembly 300according to an exemplary embodiment of the present invention and astructure thereof will be described below in brief with reference toFIG. 22C. In a liquid crystal display panel assembly 300 illustrated inFIG. 22C, one lower color filter among overlapping color filters has,for example, a concave cross section according to an exemplaryembodiment of the present invention. In addition, an overlapping portionof one color filter overlapping a side of another color filter isprovided on a data line, and a light blocking member is formed on theoverlapping portion. The upper display panel 200 is manufactured asdescribed with reference to FIG. 22A. A lower display panel 100 ismanufactured as described below. For example, gate layer conductor, agate insulating layer 140, a semiconductor 154, a linear ohmic contactmember 165, a data layer conductor, and a first protection layer 181 areformed as described with reference to FIG. 22A. Color filters 230 areformed on the first protection layer 181. For example, among the primarycolor components constituting the color filters 230, two or more colorcomponents may overlap on the data line 171. To prevent the upside ofthe color filters 230 from becoming convex due to the overlapping ofprimary color components of the color filters 230, one of theoverlapping color filters 230 may be formed, for example, concave by aphoto-lithography process. The color filter layers formed to be flat inthis way ensure excellent spread of liquid crystal molecules or lighthardeners. A second protection layer 182 is formed on the color filters230. For example, the second protection layer 182 may include theabove-described inorganic insulating material. After the secondprotection layer 182 is formed, a pixel electrode layer, a lightblocking member 220, a spacer 250 (not shown) and a lower-platealignment film 291 are formed, for example, as described with referenceto FIG. 22B. The lower and upper display panels 100 and 200 formed inthis manner may have, for example, the characteristics described withreference to FIG. 22A.

A method of manufacturing a liquid crystal display panel assembly 300according to an exemplary embodiment of the present invention and astructure thereof will be described below in brief with reference toFIG. 22D. A liquid crystal display panel assembly 300 illustrated inFIG. 22D is manufactured by including a process in which boundaries ofpixels are surrounded by a light blocking member 220, and liquidmaterials for the color filters 230 are applied onto the inside of thepixels surrounded by the light blocking member 220 according to anexemplary embodiment of the present invention. The upper display panel200 is manufactured, for example, as described with reference to FIG.22A. A lower display panel 100 is manufactured as described below. Forexample, agate layer conductor, a gate insulating layer 140, asemiconductor 154, a linear ohmic contact member 165, a data layerconductor, and a first protection layer 181 are formed as described withreference to FIG. 22A. A light blocking member 220 is formed on thefirst protection layer 181. The light blocking member 220 may be formedto completely surround one pixel along boundaries of pixels, forexample, a data line 171 or a gate layer 121. By forming the lightblocking member 220 in this manner, liquid materials for the colorfilters 230 may be applied onto the inside of the light blocking member220 in the succeeding process. The liquid materials for the colorfilters 230 are applied onto the inside of the pixel surrounded by thelight blocking member 220. The liquid materials for the color filters230 may be applied and formed by, for example, the above-describedinkjet method. Forming the color filters 230 using the inkjet method cansimplify a process for manufacturing patterns of the color filters 230.A second protection layer 182 is formed on the color filters 230. Forexample, the second protection layer 182 may be made of an organicinsulating material to planarize the upside of the color filters 230.For example, a pixel electrode layer is formed on the second protectionlayer 182, a spacer 250 (not shown) is formed on the pixel electrodelayer, and a lower-plate alignment film 291 is formed on the spacer 250.The pixel electrode layer, the spacer 250, and the lower-plate alignmentfilm 291 may be formed, for example, as described with reference to FIG.22A. The lower and upper display panels 100 and 200 formed in thismanner can have, for example, the characteristics described withreference to FIG. 22A.

Liquid crystal display panel assemblies 300 illustrated in FIGS. 22E to22H have a light blocking member 220 formed on an upper display panel200 according to an exemplary embodiment of the present invention. Amethod of manufacturing a liquid crystal display panel assembly 300according to an exemplary embodiment of the present invention and astructure thereof will be described below in brief with reference toFIG. 22E. An upper display panel 200 has, for example, an uppersubstrate 210, a light blocking member 220, color filters 230, anovercoat 225, a common electrode 270, a spacer 250 (not shown), and anupper-plate alignment film 292 (shown as 34 and 36). The light blockingmember 220 is formed on the upper substrate 210 by, for example, theabove-described method corresponding thereto. The light blocking member220 may, for example, completely cover a data line 171, and may overlapsome parts of vertical connection portions 193 h situated on both sidesof the data line 171. The light blocking member 220 may be formed, forexample, to overlap a channel of a TFT. The color filters 230 are formedon the light blocking member 220 by, for example, the above-describedmethod corresponding thereto. The color filters 230 may, for example,overlap the data line 171, an opaque film adjacent to the data line 171,or the light blocking member 220 formed after the formation of the colorfilters 230. The color filters 230 may include, for example, R, G and Bcomponents, or may include red, green, blue and yellow components. Theovercoat 225 is formed on the color filters 230 to planarize a lowerlayer. The common electrode 270 is formed, for example, on the overcoat225 by the above-described method corresponding thereto. The spacer 250may be formed, for example, on the common electrode 270. The spacer 250includes, for example, a pigment constituting color filters, and may bemade of a colored substance. The spacer 250 may be, for example, blackin color. On the other hand, the spacer 250 may be formed, for example,under a lower-plate substrate film 291 (shown as 33 and 35) on the lowerdisplay panel 100. The upper-plate alignment film 292 is formed on thespacer 250 by, for example, the below-described methods of making aliquid crystal display panel assembly of a certain mode. The upper-platealignment film 292 may include, for example, a main alignment film 34and a photo hardening layer 36.

The lower display panel 100 is formed as described below. On a lowersubstrate 110 is formed a gate layer conductor including storageelectrode line's vertical portions 128. The gate layer conductor mayhave, for example, the above-described patterns 121, 123, 124 h, 124 l,124 c, 125, 126, and 127. A gate insulating layer 140 is formed on thegate layer conductor. A semiconductor 154 is formed on the gateinsulating layer 140. The semiconductor 154 may have, for example, theabove-described patterns 154 h, 154 l, and 154 c. A linear ohmic contactmember 165 is formed on the semiconductor 154. The linear ohmic contactmember 165 may have, for example, the above-described patternscorresponding thereto. On the linear ohmic contact member 165 is formeda data layer conductor including the data line 171. The data layerconductor may have, for example, the above-described patterns 173 h, 173l, 173 c, 175 h, 175 l, 175 c, and 177 c. A first protection layer 181is formed on the data layer conductor. For example, the first protectionlayer 181 may be made of the above-described inorganic material. A pixelelectrode layer is formed on the first protection layer 181. The pixelelectrode layer may have, for example, the above/below-describedpatterns 187, 189, 191 h, 191 l, 192 h, 192 l, 193 l, 194 h, 194 l, 195h, 195 l, 196, 197 h, 197 l, 198 h, 198 l, 713 h, 713 l, 715 h, 715 l,717 h, and 717 l, including vertical connection portions 193 h, and apixel electrode structure. The vertical connection portions 193 h formedon both sides of the data line 171 may, for example, overlap storageelectrode line's vertical portions 128. The lower-plate alignment film291 is formed on the pixel electrode layer by, for example, thebelow-described methods. The lower-plate alignment film 291 may include,for example, a main alignment film 33 and a photo hardening layer 35. Aliquid crystal layer 3 is formed between the upper and lower displaypanels 200 and 100. The upper and lower display panels 200 and 100manufactured in this manner can have, for example, the characteristicsdescribed in FIG. 22A. In other words, the upper display panel 200includes layers 220, 230, and 225 blocking or absorbing light, and thelower display panel 100 does not substantially include materialsblocking light. The light irradiated in the electric-field orfluorescent lithography process to form the lower-plate and upper-platealignment films 291 and 292 may be incident upon the lower display panel100. As a result, the lower-plate and upper-plate alignment films 291and 292 may be uniformly formed, and the non-hardened light hardener maybe reduced significantly, contributing to an increase in the displayquality of the liquid crystal display device.

A liquid crystal display panel assembly 300 illustrated in FIG. 22F issubstantially similar to that described in FIG. 22E except that a secondprotection layer 182 is formed between a pixel electrode layer and afirst protection layer 181. The second protection layer 182 may be madeof, for example, an organic material to planarize a lower layer.

A liquid crystal display panel assembly 300 illustrated in FIG. 22G issubstantially similar to that described in FIG. 22F except how colorfilters 230 are formed. The color filters on an upper display panelshown in FIG. 22G may be formed by, for example, the inkjet method thathas already been described with reference to FIG. 22D.

A liquid crystal display panel assembly 300 illustrated in FIG. 22H has,for example, an overcoat 225 formed on a light blocking member 220 forbarrier or planarization, compared with the liquid crystal display panelassembly 300 illustrated in FIG. 22G. After the overcoat 225 is formed,a layer of color filters 230 may be formed, for example, withinsidewalls of the light blocking member 220 and overcoat 225 by theinkjet method. The barrier may be formed in a portion where colors ofcolor filters formed in one pixel are identified. The lower and upperdisplay panels 100 and 200 with the structures illustrated in FIGS. 22Ato 22H can increase the display quality of the liquid crystal displaydevice.

In accordance with an exemplary embodiment of the present invention, theovercoat 225 illustrated in FIGS. 21A and 21B, and FIGS. 22A to 22H mayinclude, for example, an acrylic material. The acrylic material includedin the overcoat 225 may be, for example, hardened in a process offorming the overcoat 225. The overcoat 225 including the hardenedacrylic material may, for example, transmit the short-wavelength UV athigh transmittance, thereby increasing the energy or intensity of thelight being incident on the light hardener or reactive mesogen and thusas a result increasing the cross-linking rate of the light hardener orreactive mesogen.

3) Enlarged View of Region A19 Shown in FIG. 18

A structure of the region A19 shown in FIG. 18 will be described belowin detail with reference to FIGS. 18, 19A and 19B. FIG. 19A is anenlarged view of the region A19 shown in FIG. 18. Patterns of each layerformed in the region A19, for example, patterns of first and secondsubpixel electrode contact portions 192 h and 192 l and first and secondpixel electrode junction connection portions can increase unrestorationand light leakage defects of the liquid crystal display device. Patternsillustrated in FIGS. 23A to 23F and 24A to 24T are different examplesfor increasing unrestoration and light leakage defects of the liquidcrystal display device.

The unrestoration and light leakage phenomena of a liquid crystaldisplay device are described below. Unrestoration refers to a phenomenonin which transition of liquid crystal molecules from any arrangement,for example, a stable arrangement, to another arrangement is delayed. Ifa display unit of a liquid crystal display device is pressed or impactedfrom the outside while the liquid crystal display device is in use,liquid crystal molecules in a liquid crystal layer are rearranged. Therearranged liquid crystal molecules may remain in the rearranged statefor a predetermined time without returning to their original state. Inaddition, even though a data voltage is applied to a pixel electrode andan electric field is formed in a liquid crystal layer, liquid crystalmolecules arranged in a stable state may continuously maintain theprevious arrangement state, for example, a stable state in some regionswithout moving in an electric field formed on the pixel electrode. Thisphenomenon is called unrestoration of liquid crystal molecules, whichmay cause texture defects. In the pixel electrode structure illustratedin FIGS. 18 and 19A, the unrestoration phenomenon may occur due to thecharacteristics that in a region of a cross-shaped branch 195 of a firstor second subpixel and a boundary region A19 between first and secondsubpixels, liquid crystal molecules are equal in arrangement directionand thus maintain the stable state. When the display unit is not pressedor impacted from the outside, liquid crystal molecules in the region ofthe cross-shaped branch 195 and the boundary region A19 remainindependent, whereas if the display unit is impacted, liquid crystalmolecules in these regions may be rearranged in a stable arrangement inthe same direction. To address the unrestoration, e.g., to preventliquid crystal molecules from being rearranged in a stable state, thestrength and direction of an electric field may be adjusted in theregion A19 and its adjacent regions shown in FIG. 18.

Light leakage refers to a phenomenon in which external light (not shown)passes through a liquid crystal display panel assembly 300 by a liquidcrystal layer which is not controlled by a data voltage. For example,when an alignment of liquid crystal molecules in lower and upper displaypanels 100 and 200 is distorted by the external impact, the lightincident on the liquid crystal display panel assembly 300 may passthrough the liquid crystal display panel assembly 300 without beingcontrolled by the liquid crystal display device. The light leakagephenomenon may occur even when the liquid crystal display device is notdriven. In addition, when the lower and upper display panels 100 and 200are twisted, light leakage may occur as a light blocking member deviatesfrom its normal alignment or an electric field formed in a liquidcrystal layer is distorted. Because of the light leakage, the liquidcrystal display device may have, for example, texture, stain, reddish orgreenish defects. The texture or stain defects caused by the lightleakage may occur, for example, in boundary regions between pixelelectrodes. The reddish defects caused by the light leakage may make theliquid crystal display device display reddish-dominant images, therebycausing light leakage of a red color to be more visible than lightleakage of other colors. Like the reddish defects, defects of a greenishcolor or other colors constituting a basic pixel group may cause lightof any one or more colors to be more visible than light of other colors.Tapping light leakage, a kind of light leakage, may occur when theliquid crystal display device is, for example, tapped or patted. Whenthe liquid crystal display device is tapped, the lower and upper displaypanels 100 and 200 may deviate from the normal alignment by a valuewithin a range of, for example, about 10 μm to about 15 μm, and thetapping light leakage may occur due to misalignment of layers formed inthe lower and upper display panels 100 and 200.

Patterns of the first and second subpixel electrode contact portions 192h and 192 l, first and second pixel electrode junction connectionportions, a pixel electrode, and other layers, illustrated in FIG. 19A,are patterns that improve the unrestoration and light leakage defects.The first and second subpixel electrode contact portions 192 l 1 and 192l electrically connect first and second drain electrodes 175 h and 175 lto the first and second pixel electrode junction connection portions,respectively. The first and second pixel electrode junction connectionportions serve to electrically connect the first and second subpixelelectrode contact portions 192 h and 192 l to the first and secondsubpixel electrodes 191 h and 191 l, respectively. The first and secondsubpixel electrodes 191 h and 191 l receive data signals by the firstand second subpixel electrode contact portions 192 h and 192 l and thefirst and second pixel electrode junction connection portions,respectively. The first subpixel electrode contact portion 192 h and thefirst pixel electrode junction connection portion may have, for example,a concave shape formed therein.

The first pixel electrode junction connection portion may include, forexample, a first pixel electrode's horizontal connection portion 713 h,a first pixel electrode connection portion coupling point, and a firstpixel electrode's vertical connection portion 715 h. The first pixelelectrode's vertical connection portion 715 h may include, for example,two bifurcated branches, which are slanted from the first pixelelectrode's oblique connection portion 714 h connected to a first pixelelectrode's horizontal connection portion 713 h and extend in asubstantially vertical direction, and the first pixel electrode'svertical connection portion 715 h is connected to first pixelelectrode's central micro branches 197, more preferably to the microbranches 197 to the right of a cross-shaped branch's vertical portion195 v. In accordance with an exemplary embodiment of the presentinvention, a wiring of the first pixel electrode connection portioncoupling point may be the first pixel electrode's oblique connectionportion 714 h, which is formed to be oblique as illustrated in FIGS. 18and 19A. The first pixel electrode's oblique connection portion 714 hmay be, for example, slanted with respect to a wiring of the first pixelelectrode's horizontal connection portion 713 h, a polarization axis ofa polarizer, or the above-described direction D1 by a value within arange of about 30° to about 60°. The first pixel electrode's horizontalconnection portion 713 h extends, for example, in a substantiallyhorizontal direction, and electrically connects the first subpixelelectrode contact portion 192 h to the first pixel electrode's obliqueconnection portion 714 h. The first pixel electrode's horizontalconnection portion 713 h and the first pixel electrode's obliqueconnection portion 714 h are connected at an obtuse angle, while thefirst pixel electrode's horizontal connection portion 713 h and theslanted bifurcated branches are connected at an acute angle. The firstpixel electrode junction connection portion formed in this way maydisperse an electric field occurring in a region between the first andsecond subpixels 191 h and 191 l, or prevent the electric fieldoccurring in this region from affecting the first subpixel region,thereby increasing the liquid crystal molecule's unrestoration and lightleakage defects, which may occur in the first subpixel region.

In accordance with an exemplary embodiment of the present invention, thenumber of micro branches 197 connected to the first pixel electrode'svertical connection portion 715 h may be one or more. In accordance withan exemplary embodiment of the present invention, the number of wirings713 h, 714 h, and 715 h constituting the first pixel electrode junctionconnection portion may be, for example, one, or two or more, and theirwidths may fall within a range of about 2 μm to about 7 μm. A width ofthe first pixel electrode's horizontal connection portion 713 h may be,for example, greater than a width of the first pixel electrode's obliqueconnection portion 714 h. In accordance with an exemplary embodiment ofthe present invention, the first pixel electrode junction connectionportion may be constructed to facilitate easy repair of the pixelelectrode. Therefore, a line RH1 may be, for example, fused by laser torepair manufacturing defects of the first subpixel 191 h.

A second pixel electrode junction connection portion may include, forexample, a second pixel electrode's horizontal connection portion 713 l,a second pixel electrode connection portion coupling point or a secondpixel electrode's oblique connection portion 714 l, and a second pixelelectrode connection portion 717 l. The second pixel electrodeconnection portion coupling point is connected to the second pixelelectrode's horizontal connection portion 713 l extending in ahorizontal direction, and the second pixel electrode connection portion717 l. In accordance with an exemplary embodiment of the presentinvention, a wiring of the second pixel electrode connection portioncoupling point may be, for example, the second pixel electrode's obliqueconnection portion 714 l, which is formed to be oblique as illustratedin FIGS. 18 and 19A. The second pixel electrode's horizontal connectionportion 713 l overlaps, for example, a portion of a down gate line 123along a longitudinal direction of the down gate line 123. Theoverlapping second pixel electrode's horizontal connection portion 713 lblocks an electric field existing in a peripheral portion of the downgate line 123. In addition, the second pixel electrode's horizontalconnection portion 713 l may overlap, for example, a wiring thatconnects a second drain electrode 175 l to a third source electrode 173c. A longitudinal length of the second pixel electrode's horizontalconnection portion 713 l is, for example, substantially similar to alongitudinal length of the second pixel electrode 191 l. The secondpixel electrode's oblique connection portion 714 l is formed by, forexample, a wiring slanted with respect to the second pixel electrode'shorizontal connection portion 713 l, and electrically connects thesecond pixel electrode's horizontal connection portion 713 l to thesecond pixel electrode connection portion 717 l. The second pixelelectrode's oblique connection portion 714 l is connected to microbranches 197 to the left of a vertical portion 195 v of the cross-shapedbranch 195. A tilt angle between the second pixel electrode's obliqueconnection portion 714 l and the second pixel electrode's horizontalconnection portion 713 l may fall within a range of, for example, about30° to about 60°. A line width of the second pixel electrode's obliqueconnection portion 714 l may fall within a range of, for example, about2 μm to about 7 μm, and may be greater than a width of the second pixelelectrode's micro branches 197. The second pixel electrode connectionportion 717 l electrically connects the second pixel electrode's obliqueconnection portion 714 l to the second pixel electrode 191 l. The secondpixel electrode connection portion 717 l is formed in a central portionof a second pixel electrode 191 l to electrically connect the secondpixel electrode's oblique connection portion 714 l to two micro branches197 on one end of the cross-shaped branch's vertical portion 195 v. Thesecond pixel electrode connection portion 717 l has, for example, ahanger shape. In accordance with an exemplary embodiment of the presentinvention, the number of micro branches 197 connected to the secondpixel electrode's vertical connection portion 715 l may be one or more.

In accordance with an exemplary embodiment of the present invention, asecond pixel electrode's horizontal connection portion 194 l adjacent tothe second pixel electrode's horizontal connection portion 713 l isformed, for example, on both sides of the second pixel electrodeconnection portion 717 l. The second pixel electrode's horizontalconnection portion 194 l connects second pixel electrode's microbranches 197 l. The second pixel electrode's horizontal connectionportion 194 l formed, for example, on both sides of the second pixelelectrode connection portion 717 l overlaps a portion of the down gateline 123 along an extension direction of the down gate line 123. Theoverlapping second pixel electrode's horizontal connection portion 194 lblocks an electric field existing in a peripheral portion of the downgate line 123. By doing so, the second pixel electrode junctionconnection portion or second pixel electrode's horizontal connectionportion 194 l may disperse the electric field occurring in a regionbetween the first and second subpixels 190 h and 190 l, or prevent theelectric field occurring in this region from affecting the secondsubpixel region, thereby increasing the liquid crystal molecule'sunrestoration and light leakage defects, which may occur in the secondsubpixel region.

In accordance with another exemplary embodiment of the presentinvention, the second subpixel 190 l may have regions A19a and A19billustrated in FIG. 19A. In the region A19a, a second pixel electrode'svertical connection portion 193 l extends in, for example, a stairshape, overlapping a portion of a storage electrode line's verticalportion 128 (see FIG. 21B). A projection 193 a of the second pixelelectrode's vertical connection portion 193 l may be formed in a portionwhere a line width of a data line 171 or a shield common electrode 196reduces. The region A19b is substantially similar in structure to theregion A19a, so its detailed description is omitted. The structuresformed in this way contribute to blocking an electric field occurring inthe regions A19a and A19b, and reducing light leakage defects in theseregions.

In accordance with an exemplary embodiment of the present invention, thesecond pixel electrode connection portion 717 l may be constructed tofacilitate easy repair of the pixel electrode. Therefore, the line RL1may be, for example, fused by laser spot to repair manufacturing defectsof the second subpixel 190 l.

Various examples for increasing liquid crystal molecule's unrestorationand light leakage defects will be described below with reference toFIGS. 23A to 23F and 24A to 24T. While micro branches 197 constituting apixel electrode, illustrated in FIGS. 23A to 23F and 24A to 24T, have azigzag shape, micro branches 197 may have, for example, theabove-described stripe shape or a basic unit pixel electrode shapeaccording to an exemplary embodiment of the present invention. In FIGS.23A to 23F, patterns of some layers, for example, a gate layerconductor, a data layer conductor, and a pixel electrode layer, are onlyillustrated.

Referring to FIG. 23A, a first pixel electrode junction connectionportion includes a first pixel electrode's horizontal connection portion713 h and a first pixel electrode's oblique connection portion 714 h.The connection portions 713 h and 714 h, or a pixel electrode'shorizontal connection portion 713, a pixel electrode's obliqueconnection portion 714, and a pixel electrode's vertical connectionportion 715, which are to be described in connection with FIGS. 23B to23F and 24A to 24T, may be constructed by at least one wiring, andwidths thereof may fall within a range of, for example, about 2 μm toabout 7 μm. The first pixel electrode's oblique connection portion 714 hhas, for example, branches bifurcated at an end of the first pixelelectrode's horizontal connection portion 713 h, and the bifurcatedbranches have a straight line or stripe shape, and are connected tofirst pixel electrode's micro branches extending from a central portionof a bottom end of a domain to the left of a cross-shaped branch'svertical portion 195 v, thereby dispersing an electric field that causesunrestoration of liquid crystal molecules. An angle between the firstpixel electrode's oblique connection portion 714 h and the first pixelelectrode's horizontal connection portion 713 h may fall within a rangeof, for example, about 30° to about 60°. The first pixel electrode'shorizontal connection portion 713 h may have, for example, a wedge shapemaking an acute angle with the first pixel electrode's obliqueconnection portion 714 h. The wedge-shaped first pixel electrode'shorizontal connection portion 713 h may disperse an electric field byforming a singular point. The singular point is a region where anelectric field gathers or does not substantially exist, for example, aregion SP illustrated in FIG. 23A. A wiring of the first pixelelectrode's horizontal connection portion 713 h may, for example,overlap a first drain electrode 175 h. In case of manufacturing defectsof the first subpixel 190 h, the first subpixel 190 h may be repairedby, for example, fusing micro branches connected to the first pixelelectrode's oblique connection portion 714 h, along a line RHa. Thefirst pixel electrode junction connection portion formed in this mannerensures easy repair of the first subpixel electrode 191 h, and canincrease liquid crystal molecule's unrestoration and light leakagedefects, which may occur in the first subpixel region due to theabove-described reasons. In accordance with an exemplary embodiment ofthe present invention, the first pixel electrode's horizontal connectionportion 713 h may be, for example, greater in wiring width than thefirst pixel electrode's oblique connection portion 714 h.

A second pixel electrode junction connection portion includes, forexample, a second pixel electrode's horizontal connection portion 713 l,a second pixel electrode's vertical connection portion 715 l, and asecond pixel electrode connection portion 717 l. The second pixelelectrode's vertical connection portion 715 l is connected to a centralportion of a vertical portion 195 v of, for example, a cross-shapedbranch 195, thereby preventing an electric field from being distorted toone side. In accordance with an exemplary embodiment of the presentinvention, the second subpixel 190 l can be repaired by, for example,fusing the second subpixel electrode 191 l along a line RLa. The secondpixel electrode junction connection portion formed in this way ensureseasy repair of the subpixel electrode 190 l, and can increase liquidcrystal molecule's unrestoration and light leakage defects, which mayoccur in the second subpixel region due to the above-described reasons.Other elements and their structures are the same as those described withreference to FIG. 19A, so a description thereof is omitted. Lines RHb,RLb, RHc, RLc1, RLc2, RHd, RLd, RHe, RLe, RHf, RLf, R24 a, R24 b, R24 c,R24 d, R24 f, R24 g, R24 h, R24 i, R24 j, R24 k, R24 l, R24 m, R24 n,R24 o, R24 p, R24 q, R24 r and R24 s illustrated in FIGS. 23B to 23F and24A to 24T may be fused by the above-described laser spot to repair thefirst and second subpixels 190 h and 190 l.

Referring to FIG. 23B, a first pixel electrode junction connectionportion includes a first pixel electrode's horizontal connection portion713 h and a first pixel electrode's oblique connection portion 714 h.The first pixel electrode junction connection portion is substantiallysimilar to that described in FIG. 23A except that a wiring of the firstpixel electrode's oblique connection portion 714 h is in a zigzag shape,so a detailed description of other details about the first pixelelectrode junction connection portion will be omitted. A second pixelelectrode junction connection portion includes, for example, a secondpixel electrode's horizontal connection portion 713 l and a second pixelelectrode connection portion 717 l. The second pixel electrodeconnection portion 717 l extends, for example, in a vertical directionto a down gate line 123, overlapping the down gate line 123, and iselectrically connected to a second pixel electrode's horizontalconnection portion 713 l connected to a second subpixel electrodecontact portion 192 l. As the second pixel electrode connection portion717 l extends and is connected to the second pixel electrode'shorizontal connection portion 713 l, an electric field formed in thesecond subpixel electrode contact portion 192 l and the pixel electroderegion can be dispersed. Other details about the second pixel electrodejunction connection portion have been described with reference to FIG.23A.

Referring to FIG. 23C, a first pixel electrode junction connectionportion includes, for example, a first pixel electrode's obliqueconnection portion 714 h and a first pixel electrode's verticalconnection portion 715 h. In a right bottom end of a cross-shapedbranch's vertical portion 195 v, the first pixel electrode's verticalconnection portion 715 h and first pixel electrode's micro branches 197are electrically connected. Micro branches 197 connected to the firstpixel electrode's vertical connection portion 715 h may be, for example,micro branches 197 on a lower end of the cross-shaped branch's verticalportion 195 v among the micro branches 197 connected to the cross-shapedbranch's vertical portion 195 v. The first pixel electrode's obliqueconnection portion 714 h extends, for example, obliquely to electricallyconnect the first pixel electrode's vertical connection portion 715 h tothe top of a first subpixel electrode contact portion 192 h. The firstpixel electrode's oblique connection portion 714 h may be, for example,slanted against the first pixel electrode's vertical connection portion715 h by a value within a range of about 30° to about 60°. The firstpixel electrode junction connection portion formed in this mannerensures easy repair of the first subpixel electrode 191 h, and mayincrease liquid crystal molecule's unrestoration and light leakagedefects, which may occur in the first subpixel region due to theabove-described reasons.

A second pixel electrode junction connection portion includes, forexample, a second pixel electrode's horizontal connection portion 713 land second pixel electrode's vertical connection portions 715 l. Forexample, the second pixel electrode's horizontal connection portion 713l extending in the horizontal direction is electrically connected toends of the second pixel electrode's vertical connection portions 715 lat both ends of the second pixel electrode's horizontal connectionportion 713 l, and other ends of the second pixel electrode's verticalconnection portions 715 l are connected to second pixel electrode'smicro branches 197 extending from edges of two domains adjacent to adata line. As the second pixel electrode junction connection portion isformed in both end portions of the second subpixel electrode 191 l inthis way, an electric field formed in the second subpixel electrodecontact portion 192 l and the pixel electrode region can be dispersedwidely, thereby increasing the liquid crystal molecule's unrestorationand light leakage defects, which may occur in the second subpixelregion.

Referring to FIG. 23D, a first pixel electrode junction connectionportion includes, for example, a first pixel electrode's obliqueconnection portion 714 h. Micro branches 197 on the left bottom of across-shaped branch's vertical portion 195 v are electrically connectedto the first pixel electrode's oblique connection portion 714 h, and thefirst pixel electrode's oblique connection portion 714 h is connected toa subpixel electrode contact portion 192 h. The first pixel electrode'soblique connection portion 714 h may be, for example, zigzag branchesextending from the first pixel electrode's oblique connection portion714 h. The first pixel electrode junction connection portion formed inthis manner has the above-described characteristics. A second pixelelectrode junction connection portion includes, for example, a secondpixel electrode's horizontal connection portion 713 l, a second pixelelectrode's oblique connection portion 714 l, and a second pixelelectrode connection portion 717 l. The second pixel electrodeconnection portion 717 l is connected, for example, to a cross-shapedbranch's vertical portion 195 v of the second subpixel, a right end ofthe second pixel electrode connection portion 717 l is connected to ahorizontal connection portion 194LUR connected to micro branches on theright top of the second subpixel 190 l, and the horizontal connectionportion 194LUR is connected to the second subpixel electrode'shorizontal connection portion 713 l obliquely extending in thehorizontal direction. Other details, except for the just-discussedstructures, are similar to those described in connection with FIG. 19A.

Referring to FIG. 23E, a first pixel electrode junction connectionportion includes, for example, a first pixel electrode's obliqueconnection portion 714 h, a first pixel electrode's vertical connectionportion 715 h, and a first subpixel electrode contact portion 192 h. Thefirst pixel electrode junction connection portion illustrated in FIG.23E is similar to that described with reference to FIG. 19A, except thata portion where the first pixel electrode's oblique connection portion714 h and a first pixel electrode's horizontal connection portion 713 hare connected, has, for example, a wedge shape. A second pixel electrodejunction connection portion includes, for example, a second pixelelectrode's horizontal connection portion 713 l, a second pixelelectrode connection portion 717 l, and a second subpixel electrodecontact portion 192 l. The second pixel electrode's horizontalconnection portion 713 l in the horizontal direction is, for example,electrically connected to the second subpixel electrode contact portion192 l and the second pixel electrode connection portion 717 l. Thesecond pixel electrode junction connection portion is similar to thatdescribed with reference to FIG. 23B, except that micro branchesconstituting the second subpixel electrode 191 l and the second pixelelectrode connection portion 717 l have, for example, a stripe shape. Inregions A22e, micro branches 197 project by extending from a secondpixel electrode's vertical connection portion 193 l to be adjacent to adata line. The projecting micro branches may disperse or block electricfields formed by a down gate line 123, a storage electrode line'svertical portion 128, and the data line 171. The projecting microbranches in regions A22e may be formed, for example, near the edge ofthe first or second pixel electrode 191 h or 191 l adjacent to the dataline 171. The structure of the second pixel electrode's horizontalconnection portion 713 l and the characteristics of the second pixelelectrode junction connection portion are substantially similar to thosedescribed in FIG. 19A.

Referring to FIG. 23F, a first pixel electrode junction connectionportion includes, for example, a first pixel electrode's verticalconnection portion 715 h, a first pixel electrode connection portion 717h, and a first subpixel electrode contact portion 192 h. The first pixelelectrode connection portion 717 h is formed, for example, on the bottomof a cross-shaped branch's vertical portion 195 v, and electricallyconnects the first subpixel electrode contact portion 192 h connected tothe first pixel electrode's vertical connection portion 715 h, to thefirst subpixel electrode 191 h. A horizontal connection portion 717 hhformed in the first pixel electrode connection portion 717 h in, forexample, a hanger shape is connected to micro branches 197 on the bottomof the vertical portion 195 v on both sides of the vertical portion 195v. The first pixel electrode connection portion 717 h may have theabove-described characteristics. A second pixel electrode junctionconnection portion includes, for example, a second pixel electrode'shorizontal connection portion 713 l, a second pixel electrode's verticalconnection portion 715 l, and a second subpixel electrode contactportion 192 l. The second pixel electrode's horizontal connectionportion 713 l extending, for example, in the horizontal directionelectrically connects the second subpixel electrode contact portion 192l to the second pixel electrode's vertical connection portion 715 l. Thesecond pixel electrode's vertical connection portion 715 l is connectedto, for example, a plurality of micro branches projecting in thedirection of a data line 171. Arrangements of other elements are similarto those described in connection with FIG. 23C. The characteristics ofthe second pixel electrode junction connection portion are the same asdescribed above.

Various examples for increasing liquid crystal molecule's unrestorationand light leakage defects will be described below with reference toFIGS. 24A to 24T. FIGS. 24A to 24T illustrate partial patterns of apixel electrode layer in a portion of a pixel electrode and a boundaryregion between subpixel electrodes. Structures illustrated in FIGS. 24Ato 24T may be applied to pixel electrode junction connection portions offirst and second subpixel electrodes. Referring to FIG. 24A, a pixelelectrode junction connection portion includes, for example, a subpixelelectrode contact portion 192, a pixel electrode's horizontal connectionportion 713, a pixel electrode's oblique connection portion 714, and apixel electrode's vertical connection portion 715. A plurality of microbranches 197 to the right of a cross-shaped branch's vertical portion195 v are connected to the pixel electrode's vertical connection portion715. The pixel electrode's vertical connection portion 715 joins two ormore micro branches 197 in common, and is connected to the pixelelectrode's oblique connection portion 714. The pixel electrode'soblique connection portion 714 is connected to the subpixel electrodecontact portion 192 via the pixel electrode's horizontal connectionportion 713. The lines of the pixel electrode's horizontal connectionportion 713 connected to the right bottom of the subpixel electrodecontact portion 192 are connected to, for example, two oblique lines ofthe pixel electrode's oblique connection portion 714 at an angle fallingwithin a range of about 120° to about 150°. The pixel electrode junctionconnection portion formed in this way may increase the liquid crystalmolecule's unrestoration and light leakage defects.

Referring to FIG. 24B, a pixel electrode junction connection portionincludes a pixel electrode's oblique connection portion 714. Forexample, a plurality of micro branches 197 extending from the leftbottom of a cross-shaped branch's vertical portion 195 v are connectedto the pixel electrode's oblique connection portion 714, and the pixelelectrode's oblique connection portion 714 is obliquely connected to thetop of a subpixel electrode contact portion 192, and its tilt angle maybe determined by the extending micro branches 197.

Referring to FIG. 24C, a pixel electrode junction connection portionincludes, for example, a pixel electrode's horizontal connection portion713 and a pixel electrode's vertical connection portion 715. A pluralityof micro branches 197 on the pixel electrode's corner in a regionadjacent to a data line 171 (not shown) are connected to the pixelelectrode's vertical connection portion 715. This connection portion 715is, for example, separated from a horizontal connection portion 194 anda vertical connection portion 193 of the subpixel electrode. It is to benoted that the micro branches connected to the horizontal connectionportion 194 of the pixel electrode and vertical connection portion 193of the pixel electrode, and the pixel electrode's vertical connectionportion 715, the pixel electrode's horizontal connection portion 713 anda subpixel electrode contact portion 192 are made of, for example, thesame material in an integrated layer.

Referring to FIG. 24D, a pixel electrode junction connection portionincludes, for example, a pixel electrode's horizontal connection portion713 and a pixel electrode's vertical connection portion 715, provided toconnect micro branches 197 of the subpixel electrode to a subpixelelectrode contact portion 192. Other elements of the pixel electrodejunction connection portion are similar in structure to those describedin conjunction with FIG. 24C, except that the pixel electrode's verticalconnection portion 715 is connected to a pixel electrode's verticalconnection portion 193 and a part of a horizontal connection portion 194of the pixel electrode. All of the patterns illustrated in FIGS. 24A to24T, e.g., patterns including micro branches 197 of the pixel electrode,a pixel electrode junction connection portion for connecting microbranches 197 to a subpixel electrode contact portion 192, and thesubpixel electrode contact portion 192 constitute an integrated layermade of the same material.

Referring to FIG. 24E, a pixel electrode junction connection portionincludes, for example, a pixel electrode's horizontal connection portion713, a pixel electrode's vertical connection portion 715, and a pixelelectrode connection portion 717. The pixel electrode connection portion717 includes, for example, a vertical connection portion 193 of thepixel electrode and the pixel electrode's horizontal connection portion713 connected thereto, which are connected to a plurality of microbranches 197 to the left of a cross-shaped branch's vertical portion 195v. The pixel electrode's horizontal connection portion 713 extends, forexample, from the bottom of a pixel electrode's first horizontalconnection portion 194 in the horizontal direction, and is connected toa plurality of extending micro branches 197, and to the pixelelectrode's vertical connection portion 715 connected to the top of asubpixel electrode contact portion 192. A width of the pixel electrode'svertical connection portion 715 may be, for example, greater than awiring width of the pixel electrode's horizontal connection portion 713.To disperse an electric field, micro branches 197 formed on the bottomof the cross-shaped branch's vertical portion 195 v have, for example, ahanger shape extending to be connected to a pixel electrode's secondhorizontal connection portion 194′ separated from the pixel electrode'sfirst horizontal connection portion 194.

Referring to FIG. 24F, a pixel electrode junction connection portionincludes, for example, a pixel electrode's horizontal connection portion713′, a pixel electrode's vertical connection portion 715, and a pixelelectrode connection portion 717. The pixel electrode junctionconnection portion is similar in structure to that of FIG. 24E, exceptthat the pixel electrode's horizontal connection portion 713′ is, forexample, bifurcated, unlike the pixel electrode's horizontal connectionportion 713 illustrated in FIG. 24E.

Referring to FIGS. 24G and 24H, a pixel electrode junction connectionportion includes, for example, a pixel electrode's vertical connectionportion 715 and a pixel electrode connection portion 717. The pixelelectrode connection portion 717 has, for example, the above-describedhanger shape situated in the bottom of a cross-shaped branch's verticalportion 195 v. To disperse an electric field, the pixel electrodeconnection portion 717 is separated from a pixel electrode's horizontalconnection portion 194 formed on both sides thereof. In addition, thepixel electrode connection portion 717 has, for example, a secondhorizontal connection portion 194′ projecting beyond the pixelelectrode's horizontal connection portions 194 at both sides thereof.One end of the pixel electrode's vertical connection portion 715 formedin FIG. 24G is, for example, connected to one end of the secondhorizontal connection portion 194′ of the pixel electrode connectionportion 717, and another end thereof is connected to a subpixelelectrode contact portion 192. The pixel electrode's vertical connectionportion 715 shown in FIG. 24H is connected to, for example, a centralportion of the pixel electrode connection portion 717 extending from thecross-shaped branch's vertical portion 195 v.

Referring to FIG. 24I, a pixel electrode junction connection portionincludes, for example, a pixel electrode's oblique connection portion714 and a pixel electrode connection portion 717. The pixel electrodeconnection portion 717 has, for example, a hanger shape as describedabove, and its second horizontal connection portion 194′ is on the sameline as a pixel electrode's horizontal connection portion 194 connectedto a vertical connection portion 193. The pixel electrode's obliqueconnection portion 714 extends, for example, to be slanted with respectto a central portion of the second horizontal connection portion 194′ atan angle falling within a range of about 30° to about 60°, and isconnected to the top of a subpixel electrode contact portion 192.

Referring to FIGS. 24J, 24K and 24L, a pixel electrode junctionconnection portion includes, for example, a pixel electrode's verticalconnection portion 715 and a pixel electrode connection portion 717. Thepixel electrode connection portion 717 is connected to a subpixelelectrode contact portion 192 by, for example, the pixel electrode'svertical connection portion 715. The pixel electrode's verticalconnection portion 715 illustrated in FIGS. 24J and 24K may have, forexample, a notch shape. The vertical connection portion 715 illustratedin FIG. 24J has, for example, concave notches 761, a depth of which mayfall within a range of about 2.0 μm to about 5 μm. A wiring of thevertical connection portion 715 illustrated in FIG. 24K has, forexample, convex notches 763, a height of which may fall within a rangeof about 2.0 μm to about 5 μm. The pixel electrode's vertical connectionportion 715 illustrated in FIG. 24L has, for example, a groove 765formed therein, and this groove may serve as a singular point.

Referring to FIGS. 24M to 24Q, a pixel electrode junction connectionportion has, for example, a Z-shaped wiring to disperse an electricfield. The Z-shaped wiring includes, for example, first and second pixelelectrode's horizontal connection portions 713 a and 713 b, and a secondpixel electrode's oblique connection portion 714 b. The first pixelelectrode's horizontal connection portion 713 a may, for example,overlap a drain electrode line of a TFT, and the second pixelelectrode's horizontal connection portion 713 b may overlap a drainelectrode and a source electrode of the TFT. The horizontal connectionportion 713 b of, for example, the Z shape is connected to the bottom ofa subpixel electrode contact portion 192. A first pixel electrode'soblique connection portion 714 a illustrated in FIGS. 24M to 24O has,for example, a bifurcated shape having at least two micro branchesextending from micro branches 197 at the left bottom of a domain to theleft of a cross-shaped branch's vertical portion 195 v, and is slantedwith respect to the first pixel electrode's horizontal connectionportion 713 a. The second pixel electrode's oblique connection portion714 b connects the first and second pixel electrode's horizontalconnection portions 713 a and 713 b extending in the horizontaldirection, to the first pixel electrode's oblique connection portion 714a substantially in parallel, and the second pixel electrode's horizontalconnection portion 713 b is connected to the bottom of the subpixelelectrode contact portion 192.

The first pixel electrode's oblique connection portion 714 a illustratedin FIG. 24N has, for example, a concave notch 761. The first pixelelectrode's oblique connection portion 714 a illustrated in FIG. 24Ohas, for example, a convex notch 763. A size of the notches may be thesame as those just described above. A Z-shaped wiring illustrated inFIG. 24P is similar to the above-described ones of FIGS. 24M to 24Oexcept that it has a first pixel electrode's horizontal connectionportion 713 a extending to and connecting with a pixel electrode'svertical connection portion 193 to which micro branches 197 areconnected. A Z-shaped wiring illustrated in FIG. 24Q is similar to theabove-described ones of FIGS. 24M to 24O except, for example, that aplurality of branches of a first pixel electrode's oblique connectionportion 714 a, extending from the left bottom of a domain to the left ofa cross-shaped branch's vertical portion 195 v, are connected to a firstpixel electrode's horizontal connection portion 713 a.

Referring to FIG. 24R, a pixel electrode junction connection portionincludes, for example, a pixel electrode's horizontal connection portion713, first and second pixel electrode's oblique connection portions 714a and 714 b, a pixel electrode's vertical connection portion 715, and apixel electrode connection portion 717. The pixel electrode connectionportion 717 has, for example, the above-described hanger shape. One endof a second horizontal connection portion 194′ of the pixel electrodeconnection portion 717 is, for example, obliquely connected to one endof a subpixel electrode contact portion 192 by the first pixelelectrode's oblique connection portion 714 a, and another portion of thesecond horizontal connection portion 194′ is connected to the rightbottom of the subpixel electrode contact portion 192 through the pixelelectrode's vertical connection portion 715, the second pixelelectrode's oblique connection portion 714 b, and the pixel electrode'shorizontal connection portion 713. An angle made between the pixelelectrode's horizontal connection portion 713 and the second pixelelectrode's oblique connection portion 714 b may fall within a range of,for example, about 30° to about 60°.

Referring to FIG. 24S, a pixel electrode junction connection portionincludes, for example, first and second pixel electrode's obliqueconnection portions 714 a and 714 b, and a pixel electrode connectionportion 717. The pixel electrode connection portion 717 includes, forexample, a plurality of micro branches 197 which are symmetrical about across-shaped branch's vertical portion 195 v. The first pixelelectrode's oblique connection portion 714 a is connected to a pluralityof the micro branches 197 and to the second pixel electrode's obliqueconnection portion 714 b which is obliquely connected to the top of asubpixel electrode contact portion 192. The first and second pixelelectrode's oblique connection portions 714 a and 714 b are connected,for example, at a right angle, and a groove 765 may be formed in thefirst pixel electrode's oblique connection portion 714 a. The pixelelectrode's oblique connection portions 714 a and 714 b are, forexample, symmetrical about the cross-shaped branch's vertical portion195 v.

Referring to FIG. 24T, a pixel electrode junction connection portionincludes, for example, first and second pixel electrode junctionconnection portions 771 and 773. The first pixel electrode junctionconnection portion 771 includes, for example, a first pixel electrode'shorizontal connection portion 713 a, a first pixel electrode's obliqueconnection portion 714 a, and a first pixel electrode's verticalconnection portion 715 a. The first pixel electrode's verticalconnection portion 715 a connects, for example, a pixel electrode'shorizontal connection portion 194 formed at the left bottom of a domainto the left of a cross-shaped branch's vertical portion 195 v, to thefirst pixel electrode's oblique connection portion 714 a. The firstpixel electrode's vertical connection portion 715 a may include, forexample, two branches. The first pixel electrode's oblique connectionportion 714 a may be, for example, substantially similar in tilt angleto micro branches 197 formed on the pixel electrode. The first pixelelectrode's oblique connection portion 714 a may be, for example,slanted with respect to the first pixel electrode's vertical connectionportion 715 a at an angle falling within a range of about 30° to about60°. The first pixel electrode's horizontal connection portion 713 aconnects the first pixel electrode's oblique connection portion 714 a tothe top of a subpixel electrode contact portion 192. The second pixelelectrode junction connection portion 773 includes, for example, asecond pixel electrode's horizontal connection portion 713 b, a secondpixel electrode's oblique connection portion 714 b, and a second pixelelectrode's vertical connection portion 715 b. The second pixelelectrode's vertical connection portion 715 b connects a pixelelectrode's horizontal connection portion 194 formed at the right bottomdomain of the cross-shaped branch's vertical portion 195 v adjacent tothe domain to which the first pixel electrode junction connectionportion 771 is connected, to the second pixel electrode's obliqueconnection portion 714 b. The second pixel electrode's verticalconnection portion 715 b may have, for example, two branches. The secondpixel electrode's oblique connection portion 714 b may be substantiallysimilar in tilt angle to the micro branches 197 formed on the pixelelectrode. The second pixel electrode's oblique connection portion 714 bmay be, for example, slanted with respect to the second pixelelectrode's vertical connection portion 715 b at an angle falling withina range of about 30° to about 60°. The second pixel electrode'shorizontal connection portion 713 b connects the second pixelelectrode's oblique connection portion 714 b to the top of the subpixelelectrode contact portion 192. The pixel electrode junction connectionportion formed in this manner can increase the liquid crystal molecule'sunrestoration and light leakage defects.

In an exemplary embodiment of the present invention that can increasethe unrestoration of liquid crystal molecules, an electric field formedin a domain region and an electric field formed in a non-domain regionmay be, for example, substantially symmetrical about a straight lightthat is perpendicular to lower and upper display panels. The domainregion may be a region in which micro branches 197 are formed, in theregion A19 illustrated in FIG. 19A, and the non-domain region may be aregion in which micro branches 197 are not formed, or a region in whicha light blocking member 220 is formed. A tilt direction of an alignmentfilm, made between the domain region and the non-domain region, may be,for example, substantially perpendicular to the direction of liquidcrystal molecules, formed in the domain region.

A liquid crystal display panel assembly 300 according to an exemplaryembodiment of the present invention will be described in detail belowwith reference to FIGS. 25 to 27B. In the liquid crystal display panelassembly 300, gate lines are arranged in parallel to longer sides of aunit pixel electrode according to an exemplary embodiment of the presentinvention, to reduce the number of drive Integrated Circuits (ICs)constituting a data driver 500. By doing so, the liquid crystal displaypanel assembly 300 configured in this manner and the rest thereof havingany of the above-described liquid crystal display panel assemblies'structures and pixel electrode layers' patterns, makes it possible tofurther increase the display quality of the liquid crystal displaydevice and reduce the manufacturing cost. FIG. 25 is a diagramillustrating a schematic layout of a pixel of a liquid crystal displaypanel assembly 300 according to an exemplary embodiment of the presentinvention. To express a pixel structure in brief, patterns of a gatelayer conductor, a data layer conductor, contact holes 185, and a pixelelectrode layer are selectively arranged in the layout of the pixelillustrated in FIG. 25. FIGS. 26A to 26C illustrate patterns for majorlayers of the pixel structure illustrated in FIG. 25. Specifically,FIGS. 26A to 26C illustrate a gate layer conductor pattern, a data layerconductor pattern, and a pixel electrode layer pattern including a pixelelectrode in the pixel layout illustrated in FIG. 25, respectively.FIGS. 27A and 27B are cross-sectional views taken along lines 27 a-27 a′and 27 b-27 b′ of the pixel layout illustrated in FIG. 25, respectively.The cross-sectional views illustrated in FIGS. 27A and 27B additionallyshow several layers omitted in FIG. 25. In the cross-sectional views ofthe liquid crystal display panel assembly 300, illustrated in FIGS. 27Aand 27B, cross sections along the directions 27 a and 27 b are crosssections taken along the cutting-plane lines shown in FIG. 25 when thepixel structure of FIG. 25 is arranged in the form of a matrixconsisting of rows and columns. In the following description made withreference to FIGS. 25 to 27B, as the stacking order for lower and upperdisplay panels 100 and 200 has been described with reference to FIGS. 3to 4C, a detailed description thereof is omitted. In addition, aduplicate description for similar elements made in connection with FIGS.3 to 4C and 18 to 21B will be omitted.

A layout of lower and upper display panels 100 and 200 of a liquidcrystal display panel assembly 300 will be described in detail belowwith reference to FIGS. 25 to 27B. A gate layer conductor is formed on alower substrate 110, and includes, for example, a plurality of gatelines 121 n and 121 n+1, a down gate line 123, and a plurality of gateelectrodes 124 h, 124 l, and 124 c. A data layer conductor is formed ona linear ohmic contact member 165, and includes, for example, a dataline 171, a first source electrode 173 h, a second source electrode 173l, a third source electrode 173 c, a first drain electrode 175 h, asecond drain electrode 175 l, a third drain electrode 175 c, and a thirddrain electrode's extension portion 177 c. A pixel electrode layer isformed on a second protection layer 182, and includes, for example,first and second subpixel electrodes 191 h and 191 l, first and secondsubpixel electrode contact portions 192 h and 192 l, vertical connectionportions 193 h and 193 l, horizontal connection portions 194 h and 194l, cross-shaped branch portions 195 h and 195 l, micro branches 197 hand 197 l, first and second pixel electrode's vertical connectionportions 715 h and 715 l (not shown), and an outgassing hole cover 187(not shown).

The first and second subpixel electrodes 191 h and 191 l receive datavoltages from the data line 171 through TFTs Qh25 and Ql25 connected toan (n+1)-th gate line 121 n+1. The first subpixel electrode 191 hreceives a pixel or gray level voltage from the first subpixel electrodecontact portion 192 h by means of the shape of the pixel electrodejunction connection portion illustrated in FIG. 23B. The second subpixelelectrode 191 l is connected to the second subpixel electrode contactportion 192 l and receives a pixel or gray level voltage by means of awiring or a line extending in the direction of the down gate line 123. Awiring connecting the second subpixel electrode 191 l to the secondsubpixel electrode contact portion 192 l, may cover the down gate line123 on the whole, and may extend in the direction of the data line 171.The upper horizontal connection portions 194 h and 194 l of the firstand second subpixel electrodes 191 h and 191 l, for example, overlap ann-th gate line 121 n, while the lower horizontal connection portion 194l of the second subpixel electrode 191 l overlaps the down gate line123. Gate electrodes 124 h and 124 l constituting first and second TFTsQh25 and Ql25 extend in the direction of the data line 171, overlappingthe third drain electrode's extension portion 177 c. The first andsecond subpixel electrodes 191 h and 191 l are adjacent to each other,and micro branches 197 h and 197 l, and micro slits 199 h and 199 lformed on these electrodes have, for example, a zigzag shape. Widths ofmicro branches 197 h and micro slits 199 h formed on the first subpixelelectrode 191 h may fall within a range of, for example, about 5 μm toabout 6 μm, and the widths may gradually change from about 5 μm to about6 μm. Unit lengths of zigzag micro branches 197 or micro slits 199 maybe, for example, about 14 μm. For example, main directions of microbranches 197 or micro slits 199 may be about ±40° with respect to adirection of a cross-shaped branch 195, and zigzag angles thereof mayalso be about ±7°. Widths of micro branches 197 l and micro slits 199 lformed on the second subpixel electrode 191 l may fall within a rangeof, for example, about 5 μm to about 7 μm. In accordance with anexemplary embodiment of the present invention, widths of micro slits 199l may be uniform, while widths of micro branches 197 l may graduallyincrease by, for example, about 5 μm to about 7 μm along the arrow shownin FIGS. 25 and 26C. On the other hand, widths of micro slits 199 l maygradually increase along the arrow. Unit lengths of zigzag microbranches 197 or micro slits 199 may be, for example, about 10 μm. Maindirections of micro branches 197 or micro slits 199 may be, for example,about ±45° with respect to the direction of the cross-shaped branch 195,and zigzag angles thereof may be, for example, about ±15°.

Referring to FIGS. 27A and 27B, a light blocking member 220 formed onthe upper display panel 200 is formed, for example, between pixels, andoverlaps the down gate line 123 and the gate line 121. For example, oneend of the light blocking member 220 substantially meets with one end ofthe down gate line 123 adjacent to the pixel electrode, and another endthereof substantially meets with an end of the gate line 121 adjacent tothe pixel electrode. In the pixel structure formed in this way, unlikein the pixel structure illustrated in FIGS. 3 and 18, a longer side ofthe pixel electrode is formed in parallel to the gate line 121 accordingto an exemplary embodiment of the present invention. In other words, agate line 121 along one side of a pixel electrode is long, while itsassociated data line 171, which is along the perpendicular side of thepixel electrode, is short. Therefore, a liquid crystal display devicehaving this pixel structure may operate with a less number of data driveICs, for example, with about ⅓ of the number of data drive ICsconstituting part of a conventional liquid crystal display device,thereby reducing its manufacturing cost and improving its displayquality.

In accordance with another exemplary embodiment of the presentinvention, color filters of primary colors, formed in a basic pixelgroup, may be repeatedly and periodically formed in the direction of thedata line 171. In other words, a group of color filters consisting ofprimary colors may be repeatedly and consecutively arranged in thedirection of the data line 171. On the other hand, four different colorsmay be arranged in a basic pixel group as illustrated in FIG. 32. Astructure of the basic pixel group illustrated in FIG. 32 will bedescribed below.

Modes of Liquid Crystal Display Panel Assembly

The liquid crystal display panel assembly 300, which can be manufacturedin various ways using the display panels 100 and 200 manufactured by theabove-described methods, will be described in detail below. FIGS. 6A, 6Band 6C are schematic flowcharts illustrating methods, according toexemplary embodiments of the present invention, for manufacturing theliquid crystal display panel assembly 300 based on a Super VerticalAlignment (SVA) mode, a Surface-Controlled Vertical Alignment (SC-VA)mode, and a polarized Ultra-Violet Vertical-Alignment (UV-VA) mode,respectively, using the lower and upper display panels 100 and 200manufactured in accordance with FIGS. 1 to 5B. A process of forming thelower-plate alignment film 291 and a process of forming the upper-platealignment film 292 is substantially the same in each of the modes.Therefore, to avoid duplicate descriptions, the process of forming thelower-plate alignment film 291 will be described in detail below.

SVA Mode

First, a method for manufacturing the liquid crystal display panelassembly 300 based on the SVA mode will be described in detail withreference to FIG. 6A. In first steps S110 and S120, the lower displaypanel 100 with the pixel electrode 191 and the upper display panel 200with the common electrode 270 are manufactured using the methodsdescribed in conjunction with FIGS. 1 to 5B, respectively. A mainalignment material (not shown) is applied onto the pixel electrode 191and the common electrode 270 by, for example, inkjet or roll printing.The main alignment material is formed on inner regions of the lower andupper display panels 100 and 200, and may, for example, be partiallyapplied onto outer regions of the lower and upper display panels 100 and200. The outer region of the lower display panel 100 is a region wherepixels are not formed, to which a data voltage is applied, and the innerregion thereof is a region where pixels are formed, to which a datavoltage is applied. The outer and inner regions of the upper displaypanel 200 are regions corresponding to the outer and inner regions ofthe lower display panel 100, respectively, when the lower and upperdisplay panels 100 and 200 are assembled. The outer region may includecircuit elements that generate or transfer signals applying voltages topixel electrodes. In accordance with an exemplary embodiment of thepresent invention, a main alignment material may be applied, forexample, to make a direct contact with a spacer, color filters or aninsulating layer in some regions.

According to an exemplary embodiment of the present invention, mainalignment materials can include, for example, light absorbents bonded tothe side chain, for example, a photo-sensitizer. As the photo-sensitizerincluded in the main alignment materials absorbs the UV with awavelength of, for example, about 300 nm to about 400 nm in the processthat will be described hereinafter with reference to step S154, a lowerlayer of the main alignment materials, for example, an insulating layerof organic materials, is not damaged by a ray of light incident thereon.A photo-sensitizer may be, for example, a 2-hydroxyphenyl2H-benzotriazole derivative. The UV with a wavelength of about 300 nm toabout 400 nm may be readily absorbed by hydrogen-bonding of nitrogenatoms in benzotriazole group at ortho position with hydroxyl group ofbenzene ring which constitutes 2-hydroxyphenyl 2H-benzotriazolederivative. A 2-hydroxyphenyl 2H-benzotriazole derivative may be, forexample, 2,4-[di(2H-benzotriazole-2-yl)]-1,3-dihydroxybenzene or2,4-[di(2H-benzotriazole-2-yl)]-1,3,5-trihydroxy benzene. The structureof 2-hydroxyphenyl 2H-benzotriazole derivative may be, for example, anyone of the following formulas: PS-B1 to PS-B7.

A photo-sensitizer may include, for example, the following formulasPS-A1 and PS-A2 having an amino functional group. As the side chainwhich can be polyimidated is formed by an amino group included in thephoto-sensitizer, the photo-sensitizer having an amino group can reducethe drawback of a low molecular weight photo-sensitizer. The lowmolecular weight photo-sensitizer is included in the main alignmentmaterials as a component, and thus gas can be generated during theprocess, causing a decrease in the coating uniformity of the mainalignment materials.

where X may be H, O or (CH2)n, where n is an integer of 1 to 10. Inaddition, R1 to R5 may be hydrogen or alkyl group.

The main alignment materials including a photo-absorbent according tothe exemplary embodiments of the present invention can be representedby, for example, the following formula PI-A1, and can be manufactured asfollows. A mixture of, for example, 20 moles of TCAAH(2,3,5-tricarboxycyclopentyl acetic dianhydride), 12 moles of p-phenyldiamine, 2 mole of cholestric diamine and 2 mole of2-hydroxybenzotriazole diamine (formula PS-A1) is admixed with DMAc(N,N-dimethyl acetamide) solvent under nitrogen atmosphere at the roomtemperature to 100° C. for 48 hours. The resultant stirred intermediateproduct is, for example, admixed with ethanol with a purity of about 95%or more to obtain the precipitated polyamic acid. Then, main alignmentmaterials having the following formula PI-A1 can be prepared by, forexample, mixing about 4 wt % to about 10 wt % of polyamic acid, about0.1 wt % to about 40 wt % of heat-hardener and about 80 wt % to about 95wt % of solvent. The heat-hardener may be, for example, a low molecularweight compound of series of epoxy, and the solvent may be a mixed onehaving the ratio of about 4:about 3:about 3 of butyl lacton, NVP(N-vinylpyrrolidone) and butyl cellulose.

The main alignment materials are hardened by the below-describe process,for example, using light or heat to be a main alignment film 33. It canbe easily understood by those skilled in the art that main alignmentmaterials according to other exemplary embodiments of the presentinvention may be one of materials which can be generally used in VA modeor TN mode.

In step S140 after steps S110, S120, a liquid crystal layer 3 whichincludes liquid crystal molecules 31 and a photo-hardener (not shown) isformed between an alignment film 292 of an upper display panel 200 andmain alignment films 34 and 33 of a lower display panel 100, and thelower and upper display panels 100 and 200 are sealed by a sealant to beassembled. A below-described upper-plate common voltage applying point(not shown) may be formed between the lower and upper display panels 100and 200. A sealant is hardened by, for example, heat-hardening, visiblelight or UV. A light hardener is, for example, about 1.0 wt % or less,with respect to the liquid crystal layer 3. For example, the lighthardener may be about 0.5 wt % or less, with respect to the liquidcrystal layer 3.

According to an exemplary embodiment of the present invention, liquidcrystal molecules constituting the liquid crystal layer 3 may be amixture having monomers which is comprised of, for example, threebenzene rings pursuant to the characteristics of the present invention.LC-A monomer constituting the mixture may be, for example, about 19 wt %to about 29 wt % (e.g., about 24 wt %), LC-B monomer may be about 2 wt %to about 8 wt % (e.g., about 5 wt %), LC-C monomer may be about 1 wt %to about 5 wt % (e.g., about 3 wt %), LC-D monomer may be about 19 wt %to about 29 wt % (e.g, about 24 wt %), LC-E monomer may be about 23 wt %to about 33 wt % (e.g., about 28 wt %), LC-F monomer may be about 5 wt %to about 11 wt % (e.g., about 8 wt %), and LC-G monomer may be about 5wt % to about 11 wt % (e.g. about 8 wt %). The structural formula ofLC-A monomer is, for example,

the structural formula of LC-B monomer is, for example,

the structural formula of LC-C monomer is, for example,

the structural formula of LC-D monomer is, for example,

the structural formula of LC-E monomer is, for example,

the structural formula of LC-F monomer is, for example,

and the structural formula of LC-G monomer is, for example,

where R and R′ may be an alkyl group or an alkoxy group. This mixturemay have a rotational viscosity of, for example, about 80 to about 110mPs*s, a refractive index of, for example, about 0.088 to about 0.1080,a dielectric constant of, for example, about −2.5 to about −3.7 andliquid crystalline-isotropic phase transition temperature (Tni) of, forexample, about 70° C. to about 90° C. The liquid crystal moleculescomprised of the above mixtures do not include four benzene rings, andthus have a good restoring force. Therefore, the light-leakage defectwhich occurs due to the slow restoring of liquid crystal molecules maybe reduced. Liquid crystal molecules comprised of this mixture may beapplied to below-described SC-VA mode and polarized UV-VA mode.

The light hardener according to an exemplary embodiment of the presentinvention may be, for example, a reactive mesogen. The term “mesogen”refers to a photo-crosslinkable low-molecular or high-molecularcopolymer including a mesogen group of liquid crystalline properties. Areactive mesogen may be comprised of, for example, acrylate,methacrylate, epoxy, oxetane, vinyl-ether, styrene, or thiolene groupsand the like, and may be materials included in a reactive mesogen asdiscussed above for forming an upper alignment film. A reactive mesogenmay be a material having a rod-like, banana-like, board-like, ordisc-like structure. In addition, the above-described photo-initiator(not shown) may be additionally included in the liquid crystal layer 3.The amount of a photo initiator included in a liquid crystal layer 3 is,for example, about 0.01 wt % to about 1 wt % with respect to the totalweight of light hardener. A photo initiator absorbs UV with a longwavelength, and decomposes to produce radicals which promote thephoto-polymerization of a photo-hardener. A photo initiator may bematerials which absorb the light having a wavelength of, for example,about 300 nm to about 400 nm.

In accordance with an embodiment of the present invention, a novelRM-liquid crystalline mixture in which a reactive mesogen is mixed withliquid crystal molecules, e.g., a ZSM-7160 mixture will be describedbelow. The host liquid crystal molecules which constitute the ZSM-7160mixture comprise, for example, a dicyclohexyl group monomer and acyclohexyl-fluorinated terphenyl group monomer or a fluorinatedterphenyl group monomer according to the characteristics of the presentinvention. The ZSM-7160 mixture is a mixture of liquid crystal moleculeswith a reactive mesogen, and the reactive mesogen may be mixed into themixture in an amount of, for example, about 0.1 wt % to about 1 wt %(e.g., about 0.2 wt % to about 0.5 wt %) with respect to the totalweight of host liquid crystal molecules. For example, the host liquidcrystal molecules may comprise a dicyclohexyl group monomer in an amountof about 20 wt % to about 30 wt %, a cyclohexyl-phenylene group monomerin an amount of about 0 wt % to about 10 wt %, a dicyclohexyl-phenylenegroup monomer in an amount of about 0 wt % to about 10 wt %, acyclohexyl-phenylene-difluorinated phenylene group monomer in an amountof about 20 wt % to about 30 wt %, a cyclohexyl-ethyl-difluorinatedphenylene group monomer in an amount of about 20 wt % to about 30 wt %,a dicyclohexyl-difluorinated phenylene group monomer in an amount ofabout 5 wt % to about 10 wt %, and a cyclohexyl-fluorinated terphenylgroup or fluorinated terphenyl group monomer in an amount of about 0 wt% to about 10 wt %. A percentage by weight (wt %) of respective monomerswhich constitute host liquid crystal molecules is, for example, apercentage based on the weight of host liquid crystal molecule exceptfor solvent. The refractive index of the host liquid crystal moleculemay be, for example, about 0.08 to about 0.13.

The structural formula of a dicyclohexyl group monomer may be, forexample, represented by the following formula LC-A1.

The structural formula of a cyclohexyl-phenylene group monomer may berepresented by, for example, the following formula LC-A2.

The structural formula of a dicyclohexyl-phenylene group monomer may berepresented by, for example, the following formula LC-A3.

The structural formula of a cyclohexyl-phenylene-difluorinated phenylenegroup monomer may be represented by, for example, the following formulaLC-A4.

The structural formula of a cyclohexyl-ethyl-difluorinated phenylenegroup monomer may be represented by, for example, the following formulaLC-A5, and adjust the dielectric anisotropy and the rotational viscosityof the host liquid crystal molecule.

The structural formula of a dicyclohexyl-difluorinated phenylene groupmonomer may be represented by, for example, the following formula LC-A6,and adjust the dielectric anisotropy and the rotational viscosity of thehost liquid crystal molecule.

The structural formulas of a cyclohexyl-fluorinated terphenyl groupmonomer or a fluorinated terphenyl group monomer may be represented by,for example, the following formulas LC-A7-1 and LC-A7-2, respectively,and adjust the dielectric anisotropy and the rotational viscosity of thehost liquid crystal molecule.

where R and R′ each may be an alkyl group having 1 to 10 carbon atoms,—O—, —CH═CH—, —CO—, —OCO— or —COO—.

A reactive mesogen may be a fluorinated biphenyl dimethacrylate monomerrepresented by, for example, the following formula RM-A1.

ZSM-7160 mixture comprised of mixtures of a host liquid crystal moleculeand a reactive mesogen may include a photo initiator of, for example,about 0 wt % to about 1.0 wt % with respect to the total weight of areactive mesogen. The ZSM-7160 mixture has equal properties to those ofthe conventional RM-liquid crystalline mixture, making materials ofRM-liquid crystalline mixture diverse and inhibiting the price rise ofthe RM-liquid crystalline mixture by manufacturers.

In accordance with an exemplary embodiment of the present invention, anovel RM-liquid crystalline mixture in which a reactive mesogen is mixedwith liquid crystal molecules, e.g., DS-09-9301 mixture will bedescribed below. The host liquid crystal molecules which constituteDS-09-9301 mixture comprise a biphenyl group monomer and a quinonederivative according to the characteristics of an exemplary embodimentof the present invention. A liquid crystal display device includingDS-09-9301 mixture may have fast response speed characteristics.DS-09-9301 mixture is a mixture of liquid crystal molecules with areactive mesogen, and the reactive mesogen may be mixed into the mixturein an amount of, for example, about 0.1 wt % to about 1 wt % (e.g.,about 0.2 wt % to about 0.4 wt %) with respect to the total weight ofhost liquid crystal molecules. For example, the host liquid crystalmolecules may comprise a biphenyl group monomer in an amount of about 10wt % to about 20 wt %, a cyclohexyl-phenylene group monomer in an amountof about 0 wt % to about 10 wt %, a dicyclohexyl-phenylene group monomerin an amount of about 5 wt % to about 10 wt %, acyclohexyl-phenylene-difluorinated phenylene group monomer in an amountof about 15 wt % to about 30 wt %, a quinone derivative in an amount ofabout 15 wt % to about 30 wt %, a dicyclohexyl-difluorinated phenylenegroup monomer in an amount of about 0 wt % to about 5 wt % and acyclohexyl-ethyl-difluorinated phenylene group monomer in an amount ofabout 0 wt % to about 10 wt %. A percentage by weight (wt %) ofrespective monomers which constitute host liquid crystal molecules is apercentage based on the weight of host liquid crystal molecule exceptfor solvent. The refractive index of host liquid crystal molecule maybe, for example, about 0.08 to about 0.13.

The structural formula of a biphenyl group monomer may be representedby, for example, the following formulas LC-B1-1 or LC-B1-2, and havehigh refractive index features due to the phenyl group included therein.

The structural formula of a quinone derivative may be represented by,for example, the following formulas LC-B7-1 or LC-B7-2, and adjust thedielectric anisotropy and the rotational viscosity of the host liquidcrystal molecule. In addition, polymers of formula LC-B7-1 or LC-B7-2have high polarity, and thus the response speed of the host liquidmolecule including them can be higher.

where R, R′ or OR′ each may be an alkyl group having 1 to 10 carbonatoms, —O—, —CH═CH—, —CO—, —OCO— or —COO—.

The structural formula of a cyclohexyl-phenylene group monomer may berepresented by, for example, formula LC-A2. The structural formula of adicyclohexyl-phenylene group monomer may be represented by, for example,formula LC-A3. The structural formula of acyclohexyl-phenylene-difluorinated phenylene group monomer may beformula LC-A4. The structural formula of a dicyclohexyl-difluorinatedphenylene group monomer may be represented by, for example, formulaLC-A6. The structural formula of a cyclohexyl-ethyl-difluorinatedphenylene group monomer may be represented by, for example, formulaLC-A5. A reactive mesogen may be a monomer represented by, for example,formula RM-A1. DS-09-9301 mixture comprised of mixtures of a host liquidcrystal molecule and a reactive mesogen may include, for example, aphoto initiator of about 0 wt % to 1.0 wt % with respect to the totalweight of a reactive mesogen. A liquid crystal display device includingthe DS-09-9301 mixture may have fast response speed characteristics.

In accordance with an exemplary embodiment of the present invention,host liquid crystal molecules constituting a novel RM-liquid crystalmixture may comprise, for example, an alkenyl group monomer having acarbon double bond and a monomer of the following formula LC-C9. As analkenyl group monomer having a carbon double bond is a kind of lowviscosity monomer, a RM-liquid crystal mixture comprising this monomerhas low viscosity feature, and likewise a liquid crystal display deviceincluding it may have fast response speed characteristics. An alkenylgroup monomer having, for example, a carbon double bond may be a monomerrepresented by the following formulas LC-C8-1 or LC-C8-2, and having acarbon double bond to increase the rotational viscosity of a host liquidcrystal molecule. An alkenyl group monomer having a carbon double bondmay be included in, for example, a RM-liquid crystalline mixture in anamount of about 1 wt % to about 60 wt % with respect to the total hostliquid crystal molecules except for a solvent.

where A, B and C each may be a structure of benzene ring or cyclohexanering. At least one of X and Y has a carbon double bond of a type of

The external hydrogen atoms of each ring constituting A, B and C may besubstituted by F, Cl, and the like.

A monomer of formula LC-C9 may prevent an alkenyl group monomer fromlinking to a reactive mesogen in a RM-liquid crystalline mixture. Areactive mesogen may not be hardened by bonding a π bond of a doublebond constituting an alkenyl group monomer with a methacrylate radicalof a reactive mesogen. As a result, a liquid crystal display deviceincluding them may have afterimage defects caused by the uncuredreactive mesogen. For example, a monomer represented by formula LC-C9may be included in a RM-liquid crystalline mixture in an amount of about5 wt % or less with respect to the total host liquid crystal moleculesexcept for a solvent.

where each of Z1 to Z4 may have a structure of benzene ring orcyclohexane ring, more preferably all of Z1 to Z4 may be a benzene ring.R and R′ each may be an alkyl group having 1 to 10 carbon atoms, —O—,—CH═CH—, —CO—, —OCO—, —COO—, F or Cl. The external hydrogen atoms of Z1to Z4 may be substituted by a polar atom such as F, Cl and the like.

A reactive mesogen may be mixed with host liquid crystal molecules in anamount of, for example, about 0.05 wt % to about 1 wt % (e.g., about 0.2wt % to about 0.4 wt %) with respect to the total host liquid moleculesexcept for a solvent. A reactive mesogen may be one of materials asdescribed above or below. Such an RM-liquid crystalline mixtureincluding an alkenyl group monomer and a monomer represented by formulaLC-C9 exhibited lower rotational viscosity property of, for example,about 90 mPa·s to about 108 mPa·s than that of the conventional mixture.A liquid crystal display device including this mixture had an uncuredreactive mesogen in a less amount of, for example, about 25 ppm to about35 ppm than that of the conventional mixture, and had a black afterimagein a level of, for example, about 3 or less.

Now, processes performed in step S140 are described in detail. Forexample, the main alignment material applied in steps S110 and S120 isprimarily heated for about 100 seconds to about 140 seconds at about 80°C. to about 110° C. (e.g., about 120 seconds at about 95° C.) in stepS140. During the primary heating, a solvent of the main alignmentmaterial is, for example, vaporized, and imidized monomers havingvertical alignment properties are aligned perpendicularly to a lowerlayer, forming the main alignment film.

After the primary heating, the main alignment material is, for example,secondarily heated for about 1000 seconds to about 1400 seconds at about200° C. to about 240° C. (e.g., about 1200 seconds at about 220° C.).During the secondary heating, the main alignment material is hardened orcured, forming the main alignment film.

After the secondary heating, the main alignment film is cleaned by, forexample, DeIonized Water (DIW), and may be further cleaned by isopropylalcohol (IPA). After the cleaning, the main alignment film is dried.After the drying, a liquid crystal layer is formed on a lower or upperdisplay panel 100 or 200. The liquid crystal layer may have a mixturecomprising the above-described liquid crystal molecules and theabove-described light hardeners, the ZSM-7160 mixture, the DS-09-9301mixture, or a compound of liquid crystal molecules and theabove-described light hardeners. The lower and upper display panels 100and 200 are assembled by a sealant, with liquid crystal molecules and alight hardener included therein.

After the assembly, to increase spread properties and uniformity ofliquid crystal molecules, the lower and upper display panels 100 and 200may be annealed in a chamber at a temperature of, for example, about100° C. to about 120° C. for about 60 minutes to about 80 minutes.

In the next step S150, after the assembly, the light hardener hardenedby light becomes a photo hardening layer 35. The photo hardening layer35 and the main alignment film 33 constitute the lower-plate alignmentfilm 291.

In step S152 of step S150, an electric field is formed in the liquidcrystal layer 3 before the hardened lower-plate photo hardening layer 35is formed, and then, for example, a lithography process is undertaken.These will now be described in detail. If voltages are supplied to thepixel electrode 191 on the lower display panel 100 and the commonelectrode 270 on the upper display panel 200, an electric field isformed in the liquid crystal layer 3.

Now, a description will be made of methods for forming an electric fieldin the liquid crystal layer 3 according to exemplary embodiments of thepresent invention. These methods include a method for supplying a DirectCurrent (DC) voltage and a method for supplying a multi-step voltage.First, a method for supplying a DC voltage to the liquid crystal displaypanel assembly 300 will be described with reference to FIG. 7A. If apredetermined first voltage V1 is supplied to the gate lines 121 and thedata lines 171 of the liquid crystal display panel assembly 300 for a‘TA1’ period, the subpixel electrodes 191 h and 191 l are provided withthe first voltage V1. At this time, a ground voltage or a voltage of,for example, about a zero volt (0V) is supplied to the common electrode270. The ‘TA1’ period is, for example, about 1 second to about 300seconds (e.g., about 100 seconds). The first voltage V1 is, for example,about 5V to about 20V (e.g., about 7V to about 15V).

Now, a detailed description will be made of the movement of the liquidcrystal molecules 31 aligned by the electric field that is generated inthe liquid crystal layer 3 for the ‘TA1’ period. The ‘TA1’ period is aperiod in which the liquid crystal molecules 31 are aligned in thedirection of a fringe electric field. An electric field is generated inthe liquid crystal layer 3 by a difference between the voltage suppliedto the subpixel electrodes 191 h and 191 l and the voltage supplied tothe common electrode 270, and the liquid crystal molecules 31 havingrefractive-index anisotropy are aligned by the electric field. As theedges of the pixel electrodes 191 h and 191 l include the micro branches197 h and 197 l, micro slits 199 h and 199 l, vertical connectionportions 193 h and 193 l and horizontal connection portions 194 h and194 l, as shown in FIG. 3, the pixel electrode edges distort theelectric field, and a fringe electric field is formed in the liquidcrystal layer 3. Due to the fringe electric field, major axes of theliquid crystal molecules 31 tend to be tilted in, for example, adirection perpendicular to the edges of the micro branches 197. Next,because directions of horizontal components of the fringe electricfields generated by the edges of the neighboring micro branches 197 hand 197 l are opposed to each other, and the gap W between the microbranches 197 h and 197 l, e.g., the width W of the micro slits 199 h and199 l, is narrow, the liquid crystal molecules 31 tend to be tilted inthe direction of the electric field by the horizontal components.However, as the fringe electric field by the edges of the verticalconnection portions 193 h and 193 l and the edges the horizontalconnection portions 194 h and 194 l of the pixel electrode 191 isgreater in strength than the fringe electric field by the edges of themicro branches 197 h and 197 l, the liquid crystal molecules 31 areeventually tilted in parallel with the longitudinal direction of themicro branches 197 h and 197 l. In other words, the liquid crystalmolecules 31 are tilted in parallel with the normal direction of therelatively large fringe electric field, e.g., the longitudinal directionof the micro branches 197 h and 197 l. The liquid crystal molecules 31in the region where the parallel micro branches 197 are located make atilt angle in the same direction, forming one domain. As the microbranches 197 extend in 4 different directions in the first subpixel 190h or the second subpixel 190 l of FIG. 3, the liquid crystal molecules31 near the pixel electrode 191 are tilted in 4 different directions,and each of the subpixel electrodes 191 h and 191 l has four domains. Ifone pixel PX has a large number of domains, the side visibility of theliquid crystal display device may be excellent.

Thereafter, a predetermined exposure voltage is supplied for a ‘TD1’period in which light is irradiated to the liquid crystal display panelassembly 300, whereby the liquid crystal molecules 31 are aligned in astable state, during which the electric-field lithography process isperformed. The exposure voltage may be the same as the first voltage V1in the ‘TA1’ period. The ‘TD1’ period is, for example, about 50 secondsto about 150 seconds (e.g., about 90 seconds).

In an exemplary embodiment, the pixel electrode 191 may be providedwith, for example, the ground voltage or a voltage of about 0V, and thecommon electrode 270 may be provided with the first voltage V1 or theexposure voltage.

A method for supplying a multi-step voltage to the liquid crystaldisplay panel assembly 300 according to another exemplary embodiment ofthe present invention will be described in detail with reference to FIG.7B. As the movement of the liquid crystal molecules 31 caused by theelectric field generated in the liquid crystal layer 3 has beendescribed in detail in the description of the ‘TA1’ period in FIG. 7A, adescription thereof will be omitted.

If a predetermined second voltage is supplied to the gate lines 121 andthe data lines 171 for a ‘TA2’ period, the second voltage is supplied tothe subpixel electrodes 191 h and 191 l. At this point, the groundvoltage or a voltage of, for example, about a zero volt (0V) is suppliedto the common electrode 270. The second voltage is a voltage in the‘TA2’ period, and consists of a low voltage and a high voltage V2. Thesecond voltage is alternately supplied to the subpixel electrodes 191 hand 191 l, and has a frequency of, for example, about 0.1 Hz to about120 Hz. The low voltage may be, for example, the ground voltage or 0V,and the high voltage V2 may be higher than, for example, the maximumoperating voltage of the liquid crystal display device. The high voltageV2 is, for example, about 5V to about 60V (e.g., about 30V to about50V). The ‘TA2’ period is, for example, about 1 second to about 300seconds (e.g., about 60 seconds). The time for which the low voltage orthe high voltage V2 is maintained in the ‘TA2’ period is, for example,about 1 second. As stated above, because of the difference between thevoltage supplied to the subpixel electrodes 191 h and 191 l and thevoltage supplied to the common electrode 270, an electric field isformed in the liquid crystal layer 3. If the electric field is formed inthe liquid crystal layer 3, the liquid crystal molecules 31 are tiltedin a direction parallel to the longitudinal direction of the microbranches 197 h and 197 l, and if no electric field is formed, the liquidcrystal molecules 31 are aligned in a direction perpendicular to theupper or lower display panel 100 or 200. Because alternately supplyingthe low voltage and the high voltage V2 to the subpixel electrodes 191 hand 191 l switches on and off the electric field applied to the liquidcrystal molecules 31 in the liquid crystal layer 3, the liquid crystalmolecules 31, which are vertically aligned in the initial state, may beuniformly aligned in a desired tilt direction.

Subsequently, a voltage that gradually increases from the low voltage tothe high voltage V2 is supplied for a ‘TB2’ period, whereby the liquidcrystal molecules 31 are sequentially aligned. The ‘TB2’ period may be,for example, about 1 second to about 100 seconds (e.g., about 30seconds). Because in the ‘TB2’ period, the liquid crystal molecules 31sequentially lie down (or are tilted) in a direction parallel to thelongitudinal direction of the micro branches 197 of the pixel electrode191 in the vertically aligned state with the passage of time, irregularmovement of the liquid crystal molecules 31 may be prevented, which mayoccur when an abrupt electric field is formed in the liquid crystallayer 3.

In the next ‘TC2’ period, the liquid crystal molecules 31 are tilted ina direction parallel to the longitudinal direction of the micro branches197 of the pixel electrode 191 and then the arrangement of the liquidcrystal molecules 31 is stabilized. The ‘TC2’ period is, for example,about 1 second to about 600 seconds (e.g., about 40 seconds). During the‘TC2’ period, the high voltage V2 is consistently supplied.

Thereafter, in a ‘TD2’ period for which light is irradiated to theliquid crystal display panel assembly 300, a predetermined exposurevoltage is supplied, whereby the liquid crystal molecules 31 are alignedin a stable state, during which the electric-field lithography processis performed. The ‘TD2’ period is, for example, about 80 seconds toabout 200 seconds (e.g., about 150 seconds). The exposure voltage may bethe same as the final voltage of the second voltage. The exposurevoltage is, for example, about 5V to about 60V (, e.g., about 30V toabout 50V). For example, in an exemplary embodiment of the presentinvention, if the thickness of the liquid crystal layer 3 is about 3.6μm, the exposure voltage may be about 20V to about 40V, and if thethickness of the liquid crystal layer 3 is about 3.2 μm, the exposurevoltage may be about 10V to about 30V.

In an exemplary embodiment of the present invention, the ground voltageor a voltage of, for example, about 0V may be supplied to the subpixelelectrodes 191 h and 191 l, and a predetermined second voltage (e.g., 0Vand V2) may be supplied to the common electrode 270.

In the next step S154, the DC or multi-step voltage is supplied to thelower and upper display panels 100 and 200, and then light is irradiatedto the liquid crystal layer 3 or the lower or upper display panel 100 or200 having a surface alignment reactant while a predetermined electricfield is formed in the liquid crystal layer 3, e.g., during the TD1 orTD2 period, eventually forming a photo hardening layer. As to the lightirradiated to the liquid crystal layer 3, it may be irradiated in anyone or both directions of the lower and upper substrates 110 and 210.For example, to reduce a non-hardened light hardener and uniformly forma photo hardening layer, light may be incident in the direction of anyone of the substrate 110 of the lower display panel 100 and thesubstrate 210 of the upper display panel 200, which has fewer layersabsorbing or blocking the light.

Now, a method will be described in detail, in which the lower-platephoto hardening layer 35 is formed by a process of irradiating light tothe liquid crystal layer 3 in which an electric field is formed, e.g.,by the electric-field lithography process. With an electric fieldexisting in the liquid crystal layer 3, the liquid crystal molecules 31near the main alignment film 33 are aligned to be tilted in parallelwith the direction of the micro branches 197. A light hardener existingin the liquid crystal layer 3 is hardened by the irradiated light atsubstantially the same tilt angle as those of the liquid crystalmolecules 31 on the main alignment film 33, thus forming the photohardening layer 35. The photo hardening layer 35 is formed on the mainalignment film 33. Even after removal of the electric field formed inthe liquid crystal layer 3, a side chain polymer of the photo hardeninglayer 35 maintains the intact directionality of adjacent liquid crystalmolecules 31. The mesogen according to an exemplary embodiment of thepresent invention is a light hardener, and can maintain the intactdirectionality of the adjacent liquid crystal molecules 31 by, forexample, UV or by inducing anisotropy of the mesogen at a specifictemperature.

The ‘TD1’ or ‘TD2’ period has been described above. The light irradiatedto the liquid crystal layer 3 may be, for example, collimated UV,polarized UV, or non-polarized UV. A UV wavelength may be, for example,about 300 nm to about 400 nm. Light energy is, for example, about 0.5J/cm² to about 40 J/cm² (e.g., about 5 J/cm²). The lights hardening thelight hardener and the sealant may be different in wavelength andenergy.

In this way, if the liquid crystal molecules 31 maintain the pre-tiltangle in a direction parallel to the longitudinal direction of the microbranches 197 by the polymer of the photo hardening layer 35, the liquidcrystal molecules 31 are rapidly tilted when an electric field is formedto change the direction of the liquid crystal molecules 31, ensuring afast Response Time (RT) of the liquid crystal display device. The liquidcrystal molecules 31 near the side chain of the photo hardening layer 35have a slightly constant pre-tilt angle with respect to the verticaldirection of the lower display panel 100, but the liquid crystalmolecules 31, as they move from the photo hardening layer 35 to thecenter of the liquid crystal layer 3, may not have a constant pre-tiltangle. To increase the contrast ratio of the liquid crystal displaydevice and prevent light leakage in a no-electric field state, theliquid crystal molecules 31 in the center of the liquid crystal layer 3may not have the pre-tilt angle, unlike the liquid crystal molecules 31adjacent to the photo hardening layer 35.

In an exemplary embodiment of the present invention, as the non-hardenedlight hardener remaining in the liquid crystal layer 3 may causeafterimages or image sticking, to remove the non-hardened light hardenerexisting in the liquid crystal layer 3 or to stabilize the photohardening layers 35 and 36 having the pre-tilt angle, a process in whichlight is irradiated to the liquid crystal layer 3, e.g., the fluorescentlithography process may be performed, with no electric field formed inthe liquid crystal layer 3. In accordance with an exemplary embodimentof the present invention, in the fluorescent lithography process, lightmay be irradiated for, for example, about 20 minutes to about 80 minutes(e.g., about 40 minutes). The irradiated light may be UV which is, forexample, about 300 nm to about 390 nm in wavelength, and an illuminationof which may be, for example, about 0.05 mW/cm² to about 0.4 mW/cm² at awavelength of 310 nm.

In an exemplary embodiment, the lower-plate or upper-plate photohardening layer 35 or 36 may be formed, which has side chains of variouspre-tilt angles, based on the strength of an electric field formed inthe liquid crystal layer 3, the level of a pixel voltage, the time of avoltage supplied to pixels PX, the light energy, the amount of lightirradiation, the light irradiation time, or a combination thereof. In anexemplary embodiment, in the state where different exposure voltages aresupplied to the subpixel electrodes 191 h and 191 l, the first andsecond subpixels 190 h and 190 l having the photo hardening layers 35and 36 of different pre-tilt angles may be formed by electric-fieldlithography. In an exemplary embodiment, different exposure voltages ordifferent electric-field lithography processes may be applied accordingto the pixels so that at least one pixel, e.g., a blue pixel, among theprimary color pixels constituting a basic pixel group PS may have aphoto hardening layer having a pre-tilt angle different from those ofthe other pixels.

Polarizers (not shown) are attached to the lower and upper displaypanels 100 and 200 assembled by a sealant. The liquid crystal displaypanel assembly 300 that was assembled, with a light hardener included inthe liquid crystal layer 3, has characteristics of the SVA mode.

Now, a method for manufacturing the liquid crystal display panelassembly 300 based on the SC-VA mode will be described in detail withreference to FIGS. 6B, 8A to 8E, and 9A and 9B. A redundant descriptionof the method for manufacturing the liquid crystal display panelassembly 300 based on the SVA mode will be omitted. A method formanufacturing the liquid crystal display panel assembly 300 based on theSC-VA mode will now be described in detail.

FIG. 6B is a flowchart illustrating a method for manufacturing theliquid crystal display panel assembly 300 based on the SC-VA mode usingthe lower and upper display panels 100 and 200 manufactured inconjunction with FIGS. 1 to 5B. FIGS. 8A to 8E are cross-sectional viewsillustrating a sequential process of forming the lower-plate alignmentfilm 291 of the liquid crystal display panel assembly 300 based on theSC-VA mode according to an exemplary embodiment of the presentinvention. FIGS. 9A and 9B are diagrams schematically illustrating astep of hardening a surface light hardener to form the photo hardeninglayer 35, according to an exemplary embodiment of the present invention.

Manufacturing of the lower display panel 100 with the pixel electrode191 and the upper display panel 200 with the common electrode 270 infirst steps S210 and S220 has been described with reference to FIGS. 1to 5B.

In the next steps S231 and S232, a surface light hardener layer 35 a andthe main alignment film 33 are formed on the pixel electrode 191 and thecommon electrode 270, respectively.

A process of forming the lower-plate main alignment film 33 and thesurface light hardener layer 35 a will be described in detail withreference to FIGS. 8A to 8E. Referring to FIG. 8A, a surface alignmentreactant 10 made of a surface light hardener (not shown) and a surfacemain alignment material (not shown) is formed on the pixel electrode 191by, for example, inkjet printing or roll printing. For example, thesurface alignment reactant 10 is formed on inner regions of the lowerand upper display panels 100 and 200, and may be partially applied ontoouter regions thereof. The surface alignment reactant 10 may be formedin the outer region to prevent circuit elements formed on the outerregion from being damaged by the thermal stress occurring in a processof manufacturing the liquid crystal display device. Other lower layersof the pixel electrode 191 and the common electrode 270 have beendescribed above. In other words, the surface alignment reactant 10 is,for example, a mixture or a compound of a surface light hardener and asurface main alignment material. The surface main alignment material is,for example, a vertical alignment material that aligns the liquidcrystal molecules 31 perpendicularly to the plane of a substrate or thepixel electrode 191. The surface light hardener is, for example, afunctional material that is hardened to pre-tilt the liquid crystalmolecules 31 in a specific tilt direction with respect to the plane ofthe substrate or the pixel electrode 191. Materials of the surface mainalignment material and the surface light hardener will be describedlater.

Referring to FIG. 8B, the surface alignment reactant 10 formed on thepixel electrode 191 is primarily heated at a low temperature. Theprimary heating process is performed, for example, for about 100 secondsto about 140 seconds (e.g. about 120 seconds) at about 80° C. to about110° C. (e.g., about 95° C.). In the primary heating, a solvent of thesurface alignment reactant 10 is, for example, vaporized. Referring toFIG. 8C, the surface alignment reactant 10 is phase-separated into asurface main alignment material layer 33 a with a surface main alignmentmaterial and a surface light hardener layer 35 a with a surface lighthardener. In the surface alignment reactant 10, based on the polaritydifference, a material with a relatively large polarity becomes thesurface main alignment material layer 33 a with a surface main alignmentmaterial by moving around the pixel electrode 191, while a material witha relatively small polarity becomes the surface light hardener layer 35a with a surface light hardener by moving up from the surface mainalignment material layer 33 a. The surface main alignment material has arelatively large polarity and aligns the liquid crystal molecules 31,for example, perpendicularly to the plane of the substrate or the pixelelectrode 191. The surface light hardener layer 35 a has a relativelysmall polarity as it includes an alkylated aromatic diamine-basedmonomer achieving a non-polarity effect that weakens a side-chainpolarity. Referring to FIGS. 8D and 8E, if the surface main alignmentmaterial layer 33 a and the surface light hardener layer 35 a thatunderwent phase separation, are secondarily heated at a hightemperature, the main alignment film 33 is formed on the lower portionof reactant 10, has a relatively large polarity and aligns the liquidcrystal molecules 31 perpendicularly to the plane of the substrate orthe pixel electrode 191, while the surface light hardener layer 35 awith a relatively small polarity is formed on the upper portion ofreactant 10. As a result, the main alignment film 33 and the surfacelight hardener layer 35 a have different polarity values. The secondaryheating process may be performed, for example, for about 1000 seconds toabout 1400 seconds, (e.g., about 1200 seconds) at about 200° C. to about240° C. (e.g., about 220° C.). In accordance with an exemplaryembodiment of the present invention, in the secondary heating process,for example, polyimide (PI) formed by imidization reaction forms mainchains of the surface main alignment material layer 33 a and the surfacelight hardener layer 35 a.

In an exemplary embodiment of the present invention, when the surfacemain alignment material 32 a with a surface main alignment material andthe surface light hardener layer 35 a are separately formed on the lowerlayer of reactant 10 and the upper layer reactant 10, respectively, theprimary heating process may be omitted.

Now, the surface light hardener and the surface main alignment materialwill be described in detail. According to an exemplary embodiment of thepresent invention, in the surface alignment reactant 10, the surfacemain alignment material is, for example, about 85 mol % to about 95 mol% (e.g., about 90 mol %), and the surface light hardener is, forexample, about 5 mol % to about 15 mol % (e.g., about 10 mol %). A mol %composition ratio of the surface main alignment material and the surfacelight hardener in the surface alignment reactant 10 is computed based ona solvent not being included in the surface alignment reactant 10. Themol % composition ratio of the surface main alignment material and thesurface light hardener is substantially the same, after phase separationinto the main alignment film 33 and the surface light hardener layer 35a or after forming of the main alignment film 33 and the photo hardeninglayer 35. In an exemplary embodiment of the present invention, thesurface light hardener may have one of the aforementioned reactivemesogens. In accordance with an exemplary embodiment of the presentinvention, a solvent may be added to the surface alignment reactant 10to increase coating and printing properties so that the surfacealignment reactant 10 may be well spread on the lower or upper displaypanel 100 or 200 in a wide and thin manner. In addition, the solventfacilitates dissolution or mixing of a material constituting the surfacealignment reactant 10. The solvent may be selected from the groupcomprising, for example, chlorobenzene, dimethyl sulfoxide,dimethylformamide, N-methylpyrrolidone, γ-butyrolactone, methyl methoxybutanol, ethoxy methyl butanol, toluene, chloroform, methyl cellosolve,butyl cellosolve, butyl carbitol, tetrahydrofuran, and a combinationthereof. Other materials may be used as the solvent. The aforesaidsolvents may be applied to the foregoing or following main alignmentmaterial, surface alignment reactant 10, or polarized alignmentreactant. The solvent may be, for example, vaporized by the foregoing orfollowing primary heating, secondary heating, pre-heating, orpost-heating process.

A surface main alignment material may be a polymer comprising, forexample, a dianhydride group monomer such as an alicyclic dianhydridegroup monomer, a diamine group monomer such as an aromatic diamine groupmonomer and an aliphatic ring substituted aromatic diamine groupmonomer, and an aromatic epoxide group monomer which is a crosslinker.

For example, an alicyclic dianhydride group monomer included in thesurface main alignment material may be about 39.5 mol % to about 49.5mol % in surface alignment reactants 10, an aromatic diamine groupmonomer may be about 30.5 mol % to about 40.5 mol % in surface alignmentreactants 10, an aliphatic ring substituted aromatic diamine groupmonomer may be about 7.5 mol % to about 10.5 mol % in surface alignmentreactants 10, and an aromatic epoxide group monomer may be about 0.5 mol% to about 1.5 mol % in surface alignment reactants 10.

An alicyclic dianhydride group monomer may be a monomer represented by,for example, any one of the following formulas I to V. An alicyclicdianhydride group monomer facilitates a polymer included in a surfacemain alignment material to be dissolved in a solvent, and enhanceselectro-optic characteristics of the surface main alignment material.

An aromatic diamine group monomer may be a monomer represented by, forexample, the following formula VI. An aromatic diamine group monomer ina surface main alignment material facilitates a polymer included in asurface main alignment material to be dissolved in a solvent.

where W3 may be any one of the following formulas VII to IX

An aliphatic ring substituted aromatic diamine group monomer may be amonomer represented by, for example, the following formula X. Analiphatic ring substituted aromatic diamine group monomer in a surfacemain alignment material is a vertical alignment component, whichincreases heat resistance and chemical resistance of the surface mainalignment material.

where W2 may be either one of formula XI and formula XII as follows.

An aromatic epoxide group monomer may be a monomer represented by, forexample, the following formula XIII. The aromatic epoxide group monomerof a surface main alignment material forms a crosslinked structure,allowing polymers included in a surface main alignment material to bebonded with polymers (reactive mesogen) included in a photo initiator.In addition, an aromatic epoxide group monomer increases physicalproperties, heat resistance and chemical resistance of a layer.

where Z3 may be represented by any one of the following formulas XIV andXV.

A surface main alignment material according to an exemplary embodimentof the present invention may comprise, for example, at least oneselected from polymeric materials, for example, polysiloxane, polyamicacid, polyimide, nylon, PVA (polyvinyl alcohol), PVC and the like.

A surface light hardener may comprise a dianhydride group monomer, forexample, an alicyclic dianhydride group monomer, and a diamine groupmonomer, such as a photo-reactive diamine group monomer, an alkylatedaromatic diamine group monomer and an aromatic diamine group monomer.

For example, an alicyclic dianhydride group monomer included in asurface light hardener may be about 2.5 mol % to about 7.5 mol % insurface alignment reactants 10, a photo-reactive diamine group monomermay be about 0.75 mol % to about 2.25 mol % in surface alignmentreactants 10, an alkylated aromatic diamine group monomer may be about0.75 mol % to about 2.25 mol % in surface alignment reactants 10, and anaromatic diamine group monomer may be about 1 mol % to about 3 mol % insurface alignment reactants 10.

An alicyclic dianhydride group monomer and an aromatic diamine groupmonomer, included in a surface light hardener may be, for example, thesame as an alicyclic dianhydride group monomer and an aromatic diaminegroup monomer included in a surface main alignment material,respectively.

A photo-reactive diamine group monomer is, for example, a monomercomprising a reactive mesogen, which functions to decide the pre-tilt ofphoto hardening layers 35 and 36 and the pre-tilt direction of liquidcrystal molecules. A photo-reactive diamine group monomer may be amonomer represented by, for example, the following formula XVI, morespecifically, a monomer represented by, for example, the formula XVII.

where P1 is a reactive mesogen, and W3 is an aromatic ring, which may beany one of formulas VII to IX described above.

where X may be any one selected from methylene (CH₂), phenylene (C₆H₄),biphenylene (C₁₂H₈), cyclohexylene (C₆H₈), bicyclohexylene (C₁₂H₁₆) andphenyl-cyclohexylene (C₆H₄—C₆H₈), Y may be any one selected frommethylene (CH₂), ether (O), ester (O—C═O or O═C—O), phenylene (C₆H₄) andcyclohexylene (C₆H₈), and Z may be methyl (CH3) or H. In addition, n maybe an integer of 1 to 10. A photo-reactive diamine group monomer may bepolystyrene.

An alkylated aromatic diamine group monomer may be a monomer havingvertical alignment characteristics represented by, for example, thefollowing formula XVIII. Although a polymeric alkylated aromatic diaminegroup monomer included in a surface light hardener has a verticalalignment component, it contains an alkyl group which does not exhibit apolarity, in a side chain. Because of this, polymers in a surface lighthardener layer 35 a have less polarity than those in a surface mainalignment material layer 33 a.

where R′ and R″ are defined as follows:R′: —(CH₂)_(n)-[n=1˜10] or —O—(CH₂)_(n)-[n=1˜10] or —(O—C═O orO═C—O)—(CH₂)_(n)-[n=1˜10]R″: —(CH₂)_(n-1)—CH₃ [n=1˜10] or —O—(CH₂)_(n-1)—CH₃ [n=1˜10] or —(O—C═Oor O═C—O)—(CH₂)_(n-1)—CH₃ [n=1˜10]

In addition, W₅ may be represented by the following formula XIX.

An aromatic diamine group monomer may be a monomer represented by, forexample, the above formulas VI to IX. An aromatic diamine group monomerfacilitates a polymer constituting a surface light hardener to bedissolved in solvent. The photo initiator described above may be addedinto a surface light hardener.

For example, after the secondary heating, the surface alignment reactant10 is cleaned by DIW, and may be further cleaned by IPA. After thecleaning, the surface alignment reactants 10 are dried.

In step S240, the upper-plate common voltage applying point (not shown),the sealant and the liquid crystal layer 3 are formed between the lowerand upper display panels 100 and 200, on each of which the surface lighthardener layer 35 a and the main alignment film 33 are formed, and thenthe display panels 100 and 200 are assembled. After the drying, asealant is formed on the lower display panel 100. To increase theadhesion, the sealant may be formed on the outer region of the lowerdisplay panel 100, where the surface alignment reactant 10 is notformed. On the other hand, the sealant may be formed on the outer regionof the lower display panel 100 or the upper display panel 200 in such amanner that it may, for example, partially overlap the surface alignmentreactant 10. The sealant may include, for example, a photoinitiator thatis hardened by UV having a wavelength of about 300 nm to about 400 nm.The photoinitiator hardened at a wavelength of about 300 nm to about 400nm may be, for example, Benzyl Dimethyl Ketal (BDK, Irgacure-651) or oneof the aforesaid photoinitiators.

After the drying, the upper-plate common voltage applying point (notshown) and the liquid crystal layer 3 are formed on the upper displaypanel 200. The upper-plate common voltage applying point receives thecommon voltage Vcom provided from the outside, for example, the datadriver 500, and provides the common voltage Vcom to the common electrode270 formed on the upper display panel 200. The upper-plate commonvoltage applying point may be, for example, in direct contact with acommon voltage applying pattern (not shown) formed on the lower displaypanel 100 and the common electrode 270 formed on the upper display panel200. The common voltage applying pattern is connected to the data driver500 to receive the common voltage Vcom, and may be formed while a pixelelectrode layer is formed. The upper-plate common voltage applying pointmay be formed on the outer region of the upper display panel 200, wherethe surface alignment reactant 10 is not formed. The upper-plate commonvoltage applying point may be comprised of, for example, sphericalconductors, which are conductive and are about 4 μm or less in diameter.The liquid crystal layer 3 is formed on the region where the surfacealignment reactant 10 of the upper display panel 200 is formed, or onthe inside where the sealant is formed. The processes of forming theupper-plate common voltage applying point and the liquid crystal layer 3may be performed, for example, simultaneously. In accordance with anexemplary embodiment of the present invention, by mixing the sealant,e.g., a conductive sealant, with the conductors forming the upper-platecommon voltage applying point, the sealant and the upper-plate commonvoltage applying point may be formed of the same material in a singleprocess. In a region of the lower display panel 100, in which aconductive sealant is formed, patterns of a data layer conductor may notbe formed on a lower layer of the conductive sealant, thereby preventingthe conductive sealant from being shorted to the patterns of the datalayer conductor.

After the sealant and the liquid crystal layer 3 are formed, the lowerand upper display panels 100 and 200 are assembled in a vacuum chamberby the sealant.

In step S250, as exposure voltages are supplied to the assembled displaypanels 100 and 200 and then light is irradiated thereto, e.g., as theassembled display panels 100 and 200 undergo the electric-fieldlithography process, the lower-plate photo hardening layer 35 is formedon the lower-plate main alignment film 33 and the upper-plate photohardening layer 36 is formed on the upper-plate main alignment film 34.The main alignment films 33 and 34 and the photo hardening layers 35 and36 constitute alignment films 291 and 292, respectively.

After the assembly, the sealant is exposed to UV having a wavelength ofabout 300 nm to about 400 nm, or to a visible ray having a wavelength ofabout 400 nm or more, thereby being hardened about 80%. The UV orvisible ray may be irradiated to the sealant by being incident from theoutside of the lower display panel 100. A shield mask is located betweenthe sealant and the UV source, and shields UV so that the UV may not beirradiated to areas other than the sealant. If the UV irradiated to thesealant hardens light hardener around the sealant due to its deviation,the light hardener around the sealant is hardened in advance, causingthe liquid crystal display device to suffer from edge stain defects ataround the sealant. The light hardener around the sealant may be, forexample, a light hardener forming the alignment film, or a lighthardener existing in the liquid crystal layer 3. The visible ray may beirradiated to the sealant without the shield mask.

Thereafter, the sealant undergoes, for example, thermal curing for about70 minutes at about 100° C.

After the assembly, to increase the spread and uniformity of liquidcrystal molecules 31, the lower and upper display panels 100 and 200 areannealed in a chamber at a temperature of, for example, about 100° C. toabout 120° C. for about 60 minutes to about 80 minutes.

As a process (step S252) in which after the annealing, exposure voltagesare supplied to the assembled display panels 100 and 200 and an electricfield is formed in the liquid crystal layer 3 is substantially the sameas step S152 in the SVA mode-based manufacturing method, a descriptionthereof is omitted.

In the next step S254, a process is described, in which the photohardening layer 35 is formed by the electric-field lithography processin which light is irradiated to the assembled liquid crystal displaypanel assembly 300 while the electric field is being formed. Inaccordance with an exemplary embodiment of the present invention, afterthe electric-field lithography process, an aliphatic ring substitutedaromatic diamine-based monomer of vertical alignment components, whichis a side chain, is bonded to a polyimide, which is a main chain of themain alignment film 33, and an alkylated aromatic diamine-based monomerand a photo-reactive diamine-based monomer, which are side chains, arebonded to polyimide which is a main chain of the photo hardening layer35. As the process in which light is irradiated and then the photohardening layer 35 aligns the liquid crystal molecules 31 in step S254is the same as step S154 in the SVA mode, a detailed description thereofis omitted. To reduce non-hardened light hardener and uniformly form aphoto hardening layer, the light irradiated to the surface lighthardener layer 35 a may be incident in the direction of any one of thesubstrate 110 of the lower display panel 100 and the substrate 210 ofthe upper display panel 200, which has fewer layers absorbing orblocking the light.

Now, a process in which upon receipt of light, the surface lighthardener layer 35 a formed on the main alignment film 33 becomes thephoto hardening layer 35 will be described in detail with reference toFIGS. 9A and 9B. If an electric field is formed in the liquid crystallayer 3, surface light hardeners 43 of the surface light hardener layer35 a are aligned in substantially the same direction as that ofneighboring liquid crystal molecules 31, and the surface light hardeners43 are hardened in substantially the same direction as that of theneighboring liquid crystal molecules 31 by the incident UV. The alignedand hardened surface light hardeners 43 form the photo hardening layer35, whereby liquid crystal molecules 31 adjacent to the photo hardeninglayer 35 have a pre-tilt angle. The surface light hardeners 43 shown inFIGS. 9A and 9B are high-molecular compounds in which vertical alignmentmonomers 41 constituting the surface main alignment material andmonomers including a reactive mesogen are chemically bonded. When UV isirradiated, the surface light hardeners 43 having a reactive mesogenhave the double bond unfastened by the UV and a side-chain network 40 isadditionally formed. By such reactions, the surface light hardeners 43form the photo hardening layer 35 by UV irradiation hardening. As aresult, the photo hardening layer 35 aligned in a direction slightlytilted with respect to the normal direction of the lower substrate 110is formed on the main alignment film 33 that vertically aligns theliquid crystal molecules 31. To harden the non-hardened light hardenerand stabilize the photo hardening layer 35, for example, theaforementioned fluorescent lithography process may be performed.

As described above in connection with the SVA mode, as the photohardening layer 35 is hardened while being aligned along the tiltdirection of the liquid crystal molecules 31, the liquid crystalmolecules 31 have a pre-tilt angle in a tilt direction parallel with thelongitudinal direction of the micro branches 197 of the pixel electrode191 even in the state where no electric field is applied to the liquidcrystal layer 3.

The liquid crystal display panel assembly 300 assembled in this way hascharacteristics of the SC-VA mode. If the liquid crystal display deviceis manufactured according to the SC-VA mode, light hardeners existaround the main alignment film 33 without existing in the liquid crystallayer 3, thereby significantly reducing non-hardened light hardenersremaining in the liquid crystal layer 3. Therefore, the liquid crystaldisplay device having characteristics of the SC-VA mode reduces theafter image defects, ensuring good quality. In addition, the process ofirradiating light in the no-electric field state to harden thenon-hardened light hardeners may be omitted, thereby reducing themanufacturing cost of the liquid crystal display device.

Now, characteristics of the liquid crystal display device manufacturedbased on the SC-VA mode will be described in detail with reference toFIG. 10 and Tables 2 and 3. Table 2 shows characteristics of the liquidcrystal display device based on the SC-VA mode with respect to a changein composition ratio of the surface main alignment material and thesurface light hardener included in the surface alignment reactant 10.The alicyclic dianhydride-based monomer, aromatic diamine-based monomer,aliphatic ring substituted aromatic diamine-based monomer and aromaticepoxide-based monomer constituting the surface main alignment materialthat were used in these experiments, were, for example, a tricyclo-hexyldianhydride, a terphenyl diamine, a cholesteryl benzenediamine, and ahexaepoxy benzene derivative, respectively. In addition, the alicyclicdianhydride-based monomer, photo-reactive dianhydride-based monomer,alkylated aromatic diamine-based monomer, and aromatic diamine-basedmonomer constituting the surface light hardener that were used in theseexperiments, were, for example, a tricyclo-hexyl dianhydride, amono-methacrylic benzenediamine, a mono-alkylated phenylcyclohexybenzenediamine, and a hexaepoxy benzene derivative, respectively.

The structure of a pixel PX is substantially the same as the structureshown in FIG. 3. The width of the micro branches 197 of the pixelelectrode 191 was, for example, about 3 μm, and the cell spacing in theliquid crystal layer 3 was, for example, about 3.6 μm. The exposurevoltage was, for example, about 7.5V, and UV intensity in the fieldexposure was, for example, about 5 J/cm². The liquid crystal displaydevice was operated by charge sharing-based 1G1D driving described belowin conjunction with FIG. 11. Other conditions are the same as thoseapplied to the liquid crystal display device based on the SC-VA mode.

TABLE 2 Surface main Surface alignment light Afterimage materialhardener Response occurrence (mol %) (mol %) time (ms) time Experiment1about 95 about 0 about 168 hr to about 100 to about 5 161.1 or moreExperiment2 about 85 about 5 about 168 hr to about 95 to about 15 7.9 ormore Experiment3 about 75 about 15 about 168 hr to about 85 to about 257.5 or more Experiment4 about 65 about 25 about 168 hr to about 75 toabout 35 7.3 or more

Referring to Table 2, as can be seen from Experiment 2, when the surfacemain alignment material and the surface light hardener in the surfacealignment reactant 10 were about 85 mol % to about 95 mol % and about 5mol % to about 15 mol %, respectively, the response time of the liquidcrystal display device was about 0.0079 seconds, and no afterimage wasgenerated for 168 hours, obtaining better results compared with theother experiments.

Table 3 shows characteristics of the liquid crystal display device basedon the SC-VA mode with respect to a change in composition ratio of thephoto-reactive dianhydride-based reactive mesogen and the alkylatedaromatic diamine-based vertical alignment monomer included in thesurface light hardener. The reactive mesogen and the vertical alignmentmonomer, which were applied to these experiments, were mono-methacrylicbenzenediamine and mono-alkylated phenylcyclohexy benzenediamine,respectively. Other conditions were the same as those applied to theliquid crystal display device described in conjunction with Table 2.

TABLE 3 Vertical Reactive alignment Occurrence of Mesogen monomerResponse Black light (RM) (mol %) (mol %) time (ms) leakage Experiment5about 0.75 about 0.5 about Yes to about 2.25 to about 0.75 8.2Experiment6 about 2.25 about 0.5 about Yes to about 3.75 to about 0.757.7 Experiment7 about 0.75 about 0.75 about No to about 2.25 to about2.25 7.9 Experiment8 about 2.25 about 0.75 about Yes to about 3.75 toabout 2.25 7.4

Referring to Table 3, as can be seen from Experiment 7, when thereactive mesogen and the vertical alignment monomer in the surfacealignment reactant 10 were about 0.75 mol % to about 2.25 mol % andabout 0.75 mol % to about 2.25 mol %, respectively, the response time ofthe liquid crystal display device was about 0.0079 seconds, and thelight leakage did not occur in the black state. Accordingly, it wasfound that Experiment 7 showed excellent characteristics compared withthe other experiments.

FIG. 10 illustrates Scanning Electron Microscope (SEM) images obtainedby photographing one pixel PX of the liquid crystal display device ofthe SC-VA mode, over time. The composition ratio of the surfacealignment reactant 10 used to manufacture the liquid crystal displaydevice is as follows.

For example, an alicyclic dianhydride group monomer included in asurface main alignment material, e.g., tricyclo-hexyl dianhydride wasabout 45 mol %, an aromatic diamine group monomer, e.g., terphenyldiamine was about 36 mol %, an aliphatic ring substituted aromaticdiamine group monomer, e.g., cholesteryl benzenediamine was about 9 mol%, and an aromatic epoxide group monomer, e.g., hexaepoxy benzenederivative was about 1.25 mol %. For example, an alicyclic dianhydridegroup monomer included in a surface light hardener, e.g., tricyclo-hexyldianhydride was about 5 mol %, a photo-reactive diamine group monomer,e.g., mono-methacrylic benzenediamine was about 1.5 mol %, an alkylatedaromatic diamine group monomer, e.g., mono-alkylated phenylcyclohexylbenzenediamine was about 1.5 mol %, and an aromatic diamine groupmonomer, e.g., hexaepoxy benzene derivative was about 2 mol %. Otherconditions are the same as those applied in a liquid crystal displaydevice of Table 2. Mol % of each component applied in a liquid crystaldisplay device in Table 2, Table 3 and FIG. 10 was a mol % with respectto the surface alignment reactants 10, and a solvent was excluded fromthe composition ratio of the surface alignment reactants 10.

As can be seen from FIG. 10, no texture occurred in images of a pixel PXtaken from 0 to 0.048 seconds. In addition, the inter-gray levelresponse time of the liquid crystal display device was about 0.008seconds. Thus, the liquid crystal display device manufactured based onthe SC-VA mode had a fast response time and did not cause afterimagesand light leakage for a long time, ensuring good quality.

An alignment film of a liquid crystal display device according to anexemplary embodiment of the present invention has negative electricitycharacteristics. The photo hardening layers 35 and 36 of the alignmentfilm have the negative electricity characteristics, and they are formedby hardening the surface alignment reactant 10. As substances such as,for example, fluorine atoms (F) are bonded with a portion of moleculesof the light hardener, the surface alignment reactant 10 may have thenegative electricity characteristics. Because the photo hardening layers35 and 36 have the negative electricity characteristics, polymers havingnegative electricity characteristics, which constitute the photohardening layers 35 and 36, and liquid crystal molecules 31 in theliquid crystal layer 3 may be simultaneously aligned by the electricfield formed in the liquid crystal layer 3. As a result, the photohardening layers 35 and 36 may have a more uniform pre-tilt angle. Inaddition, when the liquid crystal display device is driven, the liquidcrystal molecules 31 in the liquid crystal layer 3 and the photohardening layers 35 and 36 having the negative electricitycharacteristics move simultaneously by the electric field, ensuring afast response time of the liquid crystal display device.

This exemplary embodiment is different from the aforementionedmanufacturing method based on the SC-VA mode in that, unlike that inFIG. 8C, the material constituting the surface alignment reactant 10 maynot be phase-separated in the process of forming the alignment film. Asdetails of this exemplary embodiment are substantially similar to thoseof the manufacturing method based on the SC-VA mode, duplicatedescriptions thereof are simplified or omitted. Since the upper andlower-plate alignment films 292 and 291 are formed in a substantiallysimilar way, the process of forming alignment films according toexemplary embodiments of the present invention will be described indetail without distinguishing between the alignment films 292 and 291.

Now, a process of forming alignment films having negative electricitycharacteristics will be described in detail. The lower display panel 100with the pixel electrode 191 and the upper display panel 200 with thecommon electrode 270 are each manufactured using the foregoing orfollowing methods corresponding thereto.

The below-stated surface alignment reactant 10 having negativeelectricity characteristics according to an exemplary embodiment of thepresent invention is applied onto the pixel electrode 191 and the commonelectrode 270 by the foregoing methods corresponding thereto. Thesurface alignment reactant 10 is formed, for example, on inner regionsof the lower and upper display panels 100 and 200, and may be partiallyapplied to outer regions thereof.

A surface alignment reactant 10 is a compound characterized by, forexample, having negative electricity characteristics and is a materialforming a main alignment film which is chemically bonded with a lighthardener linked with a material exhibiting negative electricity. A lighthardener is, for example, a material, which is cured as described aboveand then allows liquid crystal molecules 31 to be pre-tilted in acertain tilted direction with respect to substrates 110 and 210 or pixelelectrode 191 to form photo hardening layers 35 and 36. A light hardenermay be linked with a side chain of a material forming a main alignmentfilm. A light hardener may be, for example, at least one selected fromthe above-described photo-reactive polymer, reactive mesogen,photo-polymerizable material, photo-isomerizable material, and theircompounds or mixtures. A reactive mesogen with negative electricityaccording to an exemplary embodiment of the present invention is, forexample, a photo-reactive fluorinated diamine group monomer describedbelow.

A material forming a main alignment film is, for example, a verticalalignment material which allows liquid crystal molecules 31 to bevertically aligned relative to the plain of substrates 110 and 210 orpixel electrode 191. A material forming a main alignment film may be acompound of, for example, an alicyclic dianhydride group monomer and analiphatic ring substituted aromatic diamine group monomer. A materialforming a main alignment film may comprise, for example, an aromaticdiamine group monomer or a crosslinker. In addition, a material forminga main alignment film may be, for example, the surface main alignmentmaterial 32 a described above.

A surface alignment reactant 10 with negative electricity according toan exemplary embodiment of the present invention will be described indetail below. The surface alignment reactant 10 with negativeelectricity may be, for example, a polymer comprising a dianhydridegroup monomer (e.g., an alicyclic dianhydride group monomer), a diaminegroup monomer (e.g., a photo-reactive fluorinated diamine group monomer,an alkylated aromatic diamine group monomer, an aromatic diamine groupmonomer and an aliphatic ring substituted aromatic diamine groupmonomer), and a crosslinker (e.g., an aromatic epoxide group monomer).

A surface alignment reactant 10 with negative electricity according toan exemplary embodiment of the present invention is a mixture of, forexample, a polyimide (PI) group compound with a crosslinker. A polyimide(PI)-based compound is, for example, a compound in which monomersconstituting a dianhydride group monomer and a diamine group monomer arechemically bonded. A polyimide-based compound can be manufactured by,for example, an imidation process in which a dianhydride monomer andmonomers which are included in diamine monomers are mixed with eachother and dissolved in a polar solvent to liberate amino groups frommonomers included in diamine group monomers, which nucleophilic-attackan acid anhydride group of a dianhydride group monomer. Prior to theimidation process, monomers constituting, for example, a diamine groupmonomer, e.g., a photo-reactive fluorinated diamine group monomer, analkylated aromatic diamine group monomer, an aromatic diamine groupmonomer and an aliphatic ring substituted aromatic diamine group monomershould be mixed together.

A surface alignment reactant 10 with negative electricity may becomprised of, for example, an alicyclic dianhydride group monomer ofabout 44 mol % to about 54 mol % (e.g., about 49 mol %), aphoto-reactive fluorinated diamine group monomer of about 0.5 mol % toabout 1.5 mol % (e.g., about 1 mol %), an alkylated aromatic diaminegroup monomer of about 12 mol % to about 18 mol % (e.g., about 15 mol%), an aromatic diamine group monomer of about 25 mol % to about 35 mol% (e.g., about 30 mol %), an aliphatic ring substituted aromatic diaminegroup monomer of about 2 mol % to about 6 mol % (e.g., about 4 mol %),and an aromatic epoxide group monomer of about 0.5 mol % to about 1.5mol % (e.g., about 1 mol %). A mol % composition ratio of a surfacealignment reactant 10 is a mol % except for a solvent.

An alicyclic dianhydride group monomer is, for example, the same asmaterials described above with reference to FIG. 6B. An alicyclicdianhydride group monomer facilitates a polymer included in a surfacealignment reactant 10 to be dissolved in a solvent, increaseselectro-optic properties of an alignment film, for example, the VoltageHolding Ratio (VHR), and enables a Residual Direct Current (RDC) voltageto be lowered. The VHR is defined as, for example, a quantitativemeasure of which a liquid crystal layer holds the voltage charged whilethe data voltage is not applied to a pixel electrode. The VHR is idealwhen it approaches 100%. As the VHR is higher, the liquid crystaldisplay device has the better image quality. The RDC voltage is definedas, for example, a voltage that is applied to the liquid crystal layerby impurities of the ionized liquid crystal layer adsorbed to analignment film, even though a voltage is not applied from the outside.As the RDC voltage is lower, the liquid crystal display device has thebetter image quality.

A photo-reactive fluorinated diamine group monomer is cured by UV toform photo hardening layers 35 and 36. A photo-reactive fluorinateddiamine group monomer has a negative electricity property as thefluorine atom (F) therein is linked in a certain direction of benzene. Aphoto-reactive fluorinated diamine group monomer may be a monomerrepresented by, for example, the following formula XVI-F, morespecifically, a mono-methacrylic fluorinated benzenediamine groupmonomer represented by, for example, the formula XVII-F.

where P2 is a fluorinated aryl acrylate group reactive mesogen, and maybe any one selected from the following formulas XVI-F-P2-11,XVI-F-P2-21, XVI-F-P2-22, XVI-F-P2-23, XVI-F-P2-31, XVI-F-P2-32,XVI-F-P2-41, and mixtures thereof. In addition, W₃ is an aromatic ring,which may be any one of formulas VII to IX described above withreference to FIG. 6B. R′ has been described with reference to FIG. 6B.

where a fluorine (F) atom is linked to benzene, causing P2 to exhibitnegative electricity feature.

A mono-methacrylic fluorinated benzenediamine monomer is represented by,for example, the following formula XVII-F.

where n may be an integer of 1 to 6.

A mono-methacrylic fluorinated benzenediamine monomer can bemanufactured by, for example, mixing a mono-methacrylic hydroxylfluorinated biphenyl intermediate with a bromoalkyl benzenediaminederivative in a polar solvent to produce a hydroxyl group from thebiphenyl intermediate, which nucleophilic-attacks a bromo group of thediamine derivative to be broken away therefrom. A mono-methacrylichydroxy fluorinated biphenyl intermediate can be synthesized by, forexample, mixing a methacrylic chloride with a dihydroxy fluorinatedbiphenyl in a polar solvent to conduct esterification.

An alkylated aromatic diamine group monomer is, for example, the same asthe material described above with reference to FIG. 6B. An alkylatedaromatic diamine group monomer included in a surface alignment reactant10 is a monomer having, for example, vertical alignment characteristics.An alkylated aromatic diamine group monomer may have nonpolarcharacteristics.

An aromatic diamine group monomer is, for example, the same as thematerial described above with reference to FIG. 6B. An aromatic diaminegroup monomer facilitates a polymer included in a surface alignmentreactant 10 to be dissolved in a solvent.

An aliphatic ring substituted aromatic diamine group monomer is, forexample, the same as the material described above with reference to FIG.6B. The aliphatic ring substituted aromatic diamine group monomer is,for example, a monomer having vertical alignment characteristics, whichvertically aligns liquid crystal molecules with respect to the lower orupper display panel.

An aromatic epoxide group monomer is, for example, the same as thematerial described above with reference to FIG. 6B. The aromatic epoxidegroup monomer forms, for example, a crosslinked structure, enabling adianhydride group monomer to be bonded with a diamine group monomer, orenabling a dianhydride group monomer linked with a diamine group monomerto be bonded with a dianhydride group monomer. The aromatic epoxidegroup monomer increases physical properties of a film, and increases aheat resistance and a chemical resistance.

A surface alignment reactant 10 having negative electricity features maycomprise, for example, a photo initiator. The photo initiator may be,for example, one of those described above, or may be α-hydroxyketone(Irgacure-127, Ciba, Switzerland), methyl benzoylformate (Irgacure-754,Ciba, Switzerland), acrylophosphine oxide (Irgacure-819, Ciba,Switzerland), titanocene (Irgacure-784, Ciba, Switzerland),α-aminoacetophenone (Irgacure-369, Ciba, Switzerland), α-aminoketone(Irgacure-379, Ciba, Switzerland), α-hydroxyketone (Irgacure-2959, Ciba,Switzerland), oxime ester (Irgacure-OXE01, Ciba, Switzerland), oximeester (Irgacure-OXE02, Ciba, Switzerland) or acrylophosphine oxide(Irgacure-TPO, Ciba, Switzerland).

The surface alignment reactant 10 having negative electricity featuresmay comprise, for example, a reactive mesogen with negative electricalfeature, to which a chlorine atom (Cl) or a chlorine molecule (Cl2) isbonded therewith.

The surface alignment reactant 10 having negative electricity featuresmay comprise, for example, a compound in which a dianhydride groupmonomer is chemically bonded with a diamine group monomer.

In accordance with an exemplary embodiment of the present invention, thesurface alignment reactant 10 may be made by, for example, combinationof the crosslinker and the surface alignment reactant 10 having negativeelectricity characteristics.

In accordance with an exemplary embodiment of the present invention, thesurface alignment reactant 10 may be, for example, a mixture of thereactive mesogen having negative electricity characteristics and thematerial forming the main alignment film.

In accordance with an exemplary embodiment of the present invention, insome regions, the surface alignment reactant 10 may be applied, forexample, to directly contact the spacer 250, the color filter 230, orthe insulating layer 140.

The applied surface alignment reactant 10 having negative electricitycharacteristics is heated by, for example, the aforementioned primaryheating process. During the primary heating process, monomers of thereactive mesogen constituting the surface alignment reactant 10 and thevertical alignment component forming the main alignment film are alignedin a direction perpendicular to the lower layer of the surface alignmentreactant 10. In addition, the reactive mesogen molecules linked to aside chain of the material constituting the surface alignment reactant10 may be on the surface of the surface alignment reactant 10. Duringthe primary heating, the surface alignment reactant 10 having negativeelectricity characteristics may not undergo the phase separationdescribed in connection with FIG. 8C.

After the primary heating, the surface alignment reactant 10 havingnegative electricity characteristics is heated by, for example, theaforesaid secondary heating process. During the secondary heating, thesolvent of the surface alignment reactant 10 is, for example, vaporizedand the crosslinker forms a crosslinking structure, thereby forming themain alignment film.

After the secondary heating, the surface alignment reactant 10 havingnegative electricity characteristics is, for example, cleaned by DIW andmay be further cleaned by, for example, IPA. After the cleaning, thesurface alignment reactants 10 are dried.

After the drying, a sealant is formed on the lower display panel 100. Asin the foregoing methods, the sealant is formed on the outer region ofthe lower display panel 100, or may be formed on the inner region of thelower display panel 100 or the upper display panel 200 so that it maypartially overlap the surface alignment reactant 10. The sealant may bethe aforementioned material, and may be hardened by, for example, UVhaving a wavelength of about 300 nm to about 400 nm, or by thebelow-stated visible ray having a wavelength of about 400 nm or more.

After the drying, an upper-plate common voltage applying point (notshown) and a liquid crystal layer 3 are formed on the upper displaypanel 200 in the aforementioned method corresponding thereto.

After the sealant and the liquid crystal layer 3 are formed, the lowerand upper display panels 100 and 200 are assembled by the sealant in avacuum chamber.

After the assembly, the sealant, as described above, is, for example,hardened about 80% by being exposed to UV having a wavelength of about300 nm to about 400 nm, or to a visible ray having a wavelength of about400 nm or more.

Thereafter, the sealant undergoes, for example, thermal curing for about70 minutes at about 100° C.

After the bonding, to increase the spread and uniformity of liquidcrystal molecules 31, the lower and upper display panels 100 and 200 areannealed in a chamber at temperature of, for example, about 100° C. toabout 120° C. for about 60 minutes to about 80 minutes.

After the annealing, voltages are supplied to the pixel electrode 191and the common electrode 270 of the display panels 100 and 200 by the DCvoltage supply or multi-step voltage supply described in connection withFIGS. 7A and 7B. The process in which an electric field is formed in theliquid crystal layer 3 is also similar to that described in connectionwith FIGS. 7A and 7B. The reactive mesogen having no negativeelectricity characteristics is aligned to be tilted in the electricfield through interaction with liquid crystal molecules 31. However, asthe reactive mesogen molecules according to an exemplary embodiment ofthe present invention have negative electricity characteristics, theyare aligned to be tilted in the electric field together with the liquidcrystal molecules 31. Therefore, it may be good that the reactivemesogen having negative electricity characteristics can be more easilyand uniformly aligned to be tilted.

While the liquid crystal molecules 31 and the reactive mesogen polymersare aligned in a specific tilt angle, the electric-field lithographyprocess is performed, in which light is irradiated to the liquid crystaldisplay panel assembly 300. As the method in which the electric-fieldlithography process and the photo hardening layers 35 and 36 form apre-tilt angle of the liquid crystal molecules 31 is substantiallysimilar to that of the aforementioned step S254, a description thereofis made in brief.

If UV is incident while the reactive mesogen polymers and the liquidcrystal molecules 31 are aligned to be tilted, the reactive mesogen ishardened, for example, in a direction substantially similar to that ofthe surrounding liquid crystal molecules 31 by the incident UV. How theacrylate reactive group of the reactive mesogen is crosslinked orhardened by UV to form the photo hardening layers 35 and 36 has beendescribed above. The reactive mesogen hardened while being aligned,forms the photo hardening layers 35 and 36 on the main alignment film,and the liquid crystal molecules 31 adjacent to the photo hardeninglayers 35 and 36 have a pre-tilt angle by the hardened reactive mesogen.The main alignment film formed in the secondary heating process and thephoto hardening layers 35 and 36 formed by the photo hardening processform the alignment film.

For example, the aforesaid fluorescent lithography process may beperformed in accordance with an exemplary embodiment of the presentinvention.

The manufactured liquid crystal display panel assembly 300 hascharacteristics of the SC-VA mode described in connection with FIG. 6B,and has the photo hardening layers 35 and 36 having a more uniformpre-tilt angle. In other words, compared with conventional non-polarphoto hardening layers, the photo hardening layers 35 and 36 accordingto an exemplary embodiment of the present invention can uniformly form apre-tilt angle of the liquid crystal molecules 31. In addition, duringdriving of the liquid crystal display device, the photo hardening layershaving negative electricity characteristics are controlled by theelectric field formed in the liquid crystal layer 3 and the controlledphoto hardening layers control the liquid crystal molecules 31,increasing the response time of the liquid crystal molecules 31. As aresult, the liquid crystal display device according to an exemplaryembodiment of the present invention can reduce the occurrence of atexture and increase video features due to its high-speed driving. Inaddition, as the reactive mesogen has negative electricitycharacteristics, the photo hardening layers 35 and 36 may be formed by,for example, a low exposure voltage.

In accordance with an exemplary embodiment of the present invention, apolymer of vertical alignment components forming the main alignment film33/34, for example, an alkylated aromatic diamine-based monomerconstituting a diamine-based monomer may have negative electricitycharacteristics. The vertical alignment polymer having negativeelectricity characteristics facilitates fast movement of liquid crystalmolecules 31, which are controlled by an electric field. As a result,the liquid crystal display device having this vertical alignment polymermay have a fast response time.

In accordance with an exemplary embodiment of the present invention, themonomers forming the photo hardening layers 35 and 36 or the monomers ofthe vertical alignment components forming the main alignment film 33/34may have, for example, positive electricity characteristics. Thealignment film having positive electricity characteristics has the sameeffect as the aforementioned alignment film having negative electricitycharacteristics.

In accordance with an exemplary embodiment of the present invention, themonomers forming the photo hardening layers 35 and 36 or the monomers ofthe vertical alignment components forming the main alignment film 33/34may have negative or positive dielectric anisotropic characteristics.The negative or positive dielectric anisotropic characteristics mayoccur due to the inclusion of a material which is polarized by theelectric field formed in the liquid crystal layer 3. The alignment filmhaving negative or positive dielectric anisotropic characteristics hasthe same effect as the aforesaid alignment film having negativeelectricity characteristics.

Now, a description will be made of characteristics of the liquid crystaldisplay device having negative electricity characteristics, which ismanufactured by the just described method. The alignment film havingnegative electricity characteristics is formed by, for example, thesurface alignment reactant 10 having the reactive mesogen with whichfluorine atoms (F) are bonded.

For manufacturing a liquid crystal display device, a surface alignmentreactant 10 having negative electricity features may comprise, forexample, about 49 mol % of tricyclo-hexyl dianhydride as an alicyclicdianhydride group monomer, about 1 mol % of mono-methacrylic fluorinatedbenzenediamine as a photo-reactive fluorinated diamine group monomer,about 15 mol % of mono-alkylated phenylcyclohexyl benzenediamine as analkylated aromatic diamine group monomer, about 30 mol % of terphenyldiamine as an aromatic diamine group monomer, about 4 mol % ofcholesteryl benzenediamine as an aliphatic ring substituted aromaticdiamine group monomer, and about 1 mol % of hexaepoxy benzene derivativeas an aromatic epoxide group monomer. A mol % of components is a mol %with respect to a surface alignment reactant 10, and a solvent is notincluded in a component ratio of the surface alignment reactant 10.

The structure of the pixels PX of the liquid crystal display device wassubstantially the same as, for example, the structure of those in FIG.3. The width of the micro branches 197 of the pixel electrode 191 was,for example, about 3 μm, and the cell spacing in the liquid crystallayer 3 was, for example, about 3.6 μm. The exposure voltage was, forexample, about 20V, and UV intensity in the electric-field lithographyprocess was, for example, about 6.55 J/cm². UV intensity applied to thefluorescent lithography process was, for example, about 0.15 mW/cm², andthe light irradiation time was, for example, about 40 minutes. Theliquid crystal display device was operated by charge sharing-based 1G1Ddriving described above in conjunction with FIG. 11.

The liquid crystal display device with the alignment film havingnegative electricity characteristics according to an exemplaryembodiment of the present invention had the texture of an allowablelevel, and showed good quality without the occurrence of texture even athigh-speed driving of 240 Hz.

An alignment film of the liquid crystal display device according to anexemplary embodiment of the present invention has rigid verticalalignment side-chains. The rigid vertical alignment side-chains areincluded in the main alignment films 33 and 34 of the alignment films291 and 292. The main alignment films 33/34 having the rigid verticalalignment side-chains prevent the liquid crystal molecules 31 from beingexcessively pre-tilted around the alignment films. If the liquid crystalmolecules 31 are excessively pre-tilted in the vicinity of the alignmentfilms, the liquid crystal display device has light leakage defects inblack images, thereby reducing its contrast ratio or image clarity. Thealignment films having rigid vertical alignment side-chains, which aremanufactured in accordance with an exemplary embodiment of the presentinvention, reduce the light leakage defects of the liquid crystaldisplay device and increase the image quality thereof.

This exemplary embodiment is different from the aforesaid method ofmanufacturing alignment films having negative electricitycharacteristics in terms of the material constituting the surfacealignment reactant 10 and the structure of the rigid vertical alignmentcomponents linked to the side chains. In addition, intensity of the UVirradiated to the liquid crystal display panel assembly 300 may be, forexample, higher than that in the SC-VA mode-based methods describedabove in connection with FIG. 6B. As certain features of this exemplaryembodiment are substantially similar to those in the aforesaid methodfor manufacturing the alignment films having negative electricitycharacteristics, duplicate descriptions thereof are simplified oromitted. However, other features of this exemplary embodiment will bedescribed in detail, such as the material constituting the surfacealignment reactant 10, the structure of the vertical alignmentcomponents, and the intensity of the UV irradiated to the liquid crystaldisplay panel assembly 300.

Now, a process of forming an alignment film having rigid verticalalignment components will be described in detail. As described above,the surface alignment reactant 10 having rigid vertical alignmentcomponents is applied onto the pixel electrode 191 and the commonelectrode 270.

The surface alignment reactant 10 including a rigid vertical alignmentcomponent is a compound of which a light hardener having aphoto-reactive monomer film is chemically linked with a material havinga vertical alignment component and forming a main alignment. A lighthardener is, for example, at least one selected from the above-describedphoto-reactive polymer, reactive mesogen, photo-polymerizable material,photo-isomerizable material and a combination or mixture thereof, and iscured to form photo hardening layers 35 and 36. In addition, forexample, a light hardener may be linked with a side chain of materialforming a main alignment film. A material forming a main alignment filmis, for example, a vertical alignment material which allows liquidcrystal molecules to be vertically aligned with respect to the plane ofsubstrates 110 and 210 or a pixel electrode 191 as described above. Amaterial forming a main alignment film according to the presentinvention may be, for example, a compound of an alicyclic dianhydridegroup monomer and an alkylated aromatic diamine group monomer describedbelow. The alkylated aromatic diamine group monomer makes the verticalalignment material rigid, and may include, for example, a plate-typecyclic ring linked with benzene. The material forming a main alignmentfilm may comprise, for example, an aromatic diamine group monomer or acrosslinker. In addition, a material forming a main alignment film maybe the surface main alignment material 32 a described above.

A surface alignment reactant 10 having a side chain of a rigid verticalalignment component will be described in detail below. A surfacealignment reactant 10 forming an alignment film of a rigid verticalalignment side chain may be a polymer comprising, for example, adianhydride group monomer (e.g., an alicyclic dianhydride groupmonomer), a diamine group monomer (e.g., a photo-reactive diamine groupmonomer, an alkylated aromatic diamine group monomer and an aromaticdiamine group monomer), and a crosslinker (e.g., an aromatic epoxidegroup monomer).

A surface alignment reactant 10 having a side chain of a rigid verticalalignment component according to an exemplary embodiment of the presentinvention is a mixture, for example, in which a polyimide group compoundand a crosslinker are mixed together. A polyimide-based compound is, forexample, a compound of which a dianhydride group monomer is chemicallylinked with a diamine group monomer. A polyimide-based compound can bemanufactured by, for example, imidation of a dianhydride group monomerand a monomer included in a diamine group monomer as described above.Monomers constituting, for example, diamine group monomers, e.g.,photo-reactive diamine group monomers, alkylated aromatic diamine groupmonomers and aromatic diamine group monomers are mixed prior toimidation.

A surface alignment reactant 10 forming an alignment film of a rigidvertical alignment side chain is comprised of, for example, alicyclicdiahydride group monomers of about 38 mol % to about 48 mol % (e.g.,about 43 mol %), photo-reactive diamine group monomers of about 5 mol %to about 11.5 mol % (e.g., about 8.5 mol %), alkylated aromatic diaminegroup monomers of about 3.5 mol % to about 9.5 mol % (e.g., about 6.5mol %), aromatic diamine group monomers of about 23 mol % to about 33mol % (e.g., about 28 mol %), and aromatic epoxide group monomers ofabout 11 mol % to about 17 mol % (e.g., about 14 mol %). A mol %composition ratio of a surface alignment reactant 10 is a mol % exceptfor a solvent.

Alicyclic diahydride group monomers facilitate polymers included in asurface alignment reactant 10 to be dissolved in a solvent, and enableelectro-optic properties of an alignment film, for example, a VHR, to beincreased, and an RDC voltage to be decreased. A structure of alicyclicdiahydride group monomers may be, for example, a cyclobutyl dianhydridemonomer represented by, for example. the following formula XVI-RCA.

Photo-reactive diamine group monomers comprise a reactive mesogen, andare cured by irradiation of UV to form photo hardening layers 35 and 36.In addition, photo-reactive diamine group monomers function to decidethe pre-tilt of the photo hardening layers 35 and 36 and the pre-tilt ofliquid crystal molecules which are adjacent to the photo hardeninglayers 35 and 36. A structure of photo-reactive diamine group monomersmay be a monomer represented by the following formula XVI-RC or XVI-RA,more specifically, monomers of the following formula XVI-RC1, XVI-RC2,XVI-RC3, XVI-RC4, XVI-RA1, XVI-RA2, XVI-RA3, XVI-RA4, XVI-RA5 orXVI-RA6.

where XRC may be any one selected from alkyl, ether, ester, phenyl,cyclohexyl, and ester-phenyl. YRC may be any one selected from alkyl,phenyl, biphenyl, cyclohexyl, bicyclohexyl, and phenyl-cyclohexyl.

where ZRA may be any one selected from alkyl, alkyl ether, alkyl ester,alkyl phenyl ester, alkyl phenyl ether, alkyl biphenyl ester, alkylbiphenyl ether, phenyl ether, phenyl ether alkyl, biphenyl ether,biphenyl ether alkyl, cyclohexyl alkyl, bicyclohexyl alkyl, andcyclohexyl alkyl ester.

Photo-reactive diamine group monomers may be, for example, a decylcinnamoyl benzenediamine monomer or a mono-methacrylic benzenediaminemonomer. A decyl cinnamoyl benzenediamine monomer can be manufacturedby, for example, mixing a decyl cinnamoyl phenol intermediate and adiamino benzoyl chloride derivative in a polar solvent to produce amixture, and esterifying this mixture. A decyl cinnamoyl phenolintermediate can be manufactured by, for example, mixing a hydroxybenzene cinnamoyl chloride and a decyl alcohol in polar solvent toproduce a mixture, and esterifying this mixture. A mono-methacrylicbenzenediamine monomer can be manufactured by, for example, mixing ahydroxy alkyl benzenediamine derivative and a methacrylic chloride in apolar solvent to produce a mixture, and esterifying this mixture.

In an exemplary, photo-reactive diamine group monomers may beacryl-cinnamoyl hybrid benzenediamine represented by, for example,formula XVI-RD. Acryl-cinnamoyl hybrid benzenediamine monomer comprises,for example, both an acrylate reactive group and a cinnamate reactivegroup. An acrylate reactive group reacts with side chains to form acrosslinkage, and cinnamate reactive groups link with each other toincrease a pre-tilt angle.

where X may be any one selected from an alkyl group having 1 to 10carbon atoms, ether and ester, and Y may be any one selected from alkyl,phenyl, biphenyl, cyclohexyl, bicyclohexyl, and phenyl-cyclohexyl.

Alkylated aromatic diamine group monomers are monomers of, for example,a vertical alignment component. The cyclic ring linked with benzenemakes a vertical alignment rigid. Liquid crystal molecules which areadjacent to alkylated aromatic diamine group monomers are, for example,vertically aligned. A cyclic ring may be, for example, a plate-typemolecule. The structure of an alkylated aromatic diamine monomer may be,for example, octadecyl cyclohexyl benzenediamine represented by formulaXVIII-RCA1 or alkyl substituted aliphatic aromatic benzenediaminerepresented by formula XVIII-RCA2.

where XR2 may be ether or ester, YR2 may be ether, and n2 may be 10 to20. a2 and b2 may be 0 to 3, and both a2 and b2 cannot be 0 at the sametime.

Octadecyl cyclohexyl benzenediamine monomer can be manufactured by, forexample, mixing octadecyl cyclohexanol intermediate and diamino benzoylchloride derivative in a polar solvent to produce a mixture, andesterifying this mixture. Octadecyl cyclohexanol intermediate can bemanufactured by, for example, mixing bromooctadecane and cyclohexanediolin a polar solvent to produce a mixture, and nucleophilic-attackingbromo group of bromooctadecane with hydroxyl group of cyclohexanediol toliberate the bromo group.

Aromatic diamine group monomers facilitate polymers included in asurface alignment reactant 10 to be dissolved in a solvent. Thestructure of aromatic diamine group monomers may be, for example,diphenyl diamine represented by formula VI-RCA.

where X may be an aliphatic compound.

Aromatic epoxide group monomers form a crosslinked structure to increaseheat resistance and thermal resistance. Aromatic epoxide group monomersmay be, for example, an epoxy benzene derivative represented by formulaXIII-RCA.

The aforesaid photoinitiator may be added to the surface alignmentreactant 10. Unlike the surface alignment reactant 10 having negativeelectricity characteristics, the surface alignment reactant 10 havingrigid vertical alignment components may not have the polymer havingnegative electricity characteristics.

The applied surface alignment reactant 10 having rigid verticalalignment components is primarily heated by, for example, theaforementioned primary heating method. While being primarily heated, thealkylated aromatic diamine-based monomer is aligned in perpendicular tothe lower layer of the surface alignment reactant 10, and the alkylatedaromatic diamine-based monomer constituting the surface alignmentreactant 10 and consisting of reactive mesogen components constitutingthe photo-reactive diamine-based monomer and vertical alignmentcomponents forms the main alignment film. During the primary heating,the surface alignment reactant 10 may not undergo phase separationdescribed above in connection with FIG. 8C.

After undergoing the primary heating, the surface alignment reactant 10is secondarily heated by, for example, one of the aforesaid secondaryheating methods. During the secondary heating, the solvent of thesurface alignment reactant 10 is, for example, vaporized. In thesecondary heating, side chains of the reactive mesogen may be formed onthe surface of the surface alignment reactant 10. After the secondaryheating, the surface alignment reactant 10 is, for example, cleaned anddried by the aforementioned cleaning and drying methods.

After the drying, a sealant is formed by an aforementioned methodcorresponding thereto. As described above, the sealant may be hardenedin UV having a wavelength of about 300 nm to about 400 nm, or in lighthaving a wavelength of about 400 nm or more. Thereafter, in accordancewith the aforementioned methods corresponding thereto, an upper-platecommon voltage applying point (not shown) and a liquid crystal layer areformed, and the lower and upper display panels 100 and 200 areassembled. The sealant is hardened by light or heat as described above.

The assembled display panels are annealed by the aforementioned methodscorresponding thereto, and provided with voltages by the DC voltagesupply or multi-step voltage supply.

While liquid crystal molecules 31 and reactive mesogens are aligned in aspecific tilt angle by the supplied voltage, the electric-fieldlithography process is performed on the assembled liquid crystal displaypanel assembly 300 by the aforementioned field exposure method. Unlikein the method of forming alignment films having negative electricitycharacteristics, the reactive mesogens may be aligned in a specific tiltangle through interaction with the liquid crystal molecules 31. The UVirradiated to the liquid crystal display panel assembly 300 having rigidvertical alignment components according to an exemplary embodiment ofthe present invention may be, for example, greater in intensity than theaforementioned UV. In accordance with an exemplary embodiment of thepresent invention, the intensity of UV irradiated to the liquid crystaldisplay panel assembly 300 while an electric field is formed in theliquid crystal layer 3, may be, for example, about 6 J/cm² to about 17.5J/cm². For example, the intensity of the UV irradiated may be about 12J/cm². The reactive mesogen is hardened by light, forming the photohardening layers 35 and 36 on the main alignment film 33/34, and asdescribed above, the photo hardening layers 35 and 36 have a pre-tiltangle. However, as the main alignment film 33/34 according to anexemplary embodiment of the present invention has the rigid verticalalignment components, the pre-tilt angle of the photo hardening layers35 and 36 may be small. The small pre-tilt angle of the photo hardeninglayers 35 and 36 may reduce the light leakage in black images, therebyincreasing the image quality and contrast ratio of the liquid crystaldisplay device.

Thereafter, the aforementioned fluorescent lithography process may beperformed.

Through this process, the surface alignment reactant 10 having rigidvertical alignment components forms the alignment films, manufacturingthe liquid crystal display panel assembly 300. The alignment filmshaving rigid vertical alignment side-chains, manufactured according toan exemplary embodiment of the present invention, may reduce the blacklight leakage defects of the liquid crystal display device.

The liquid crystal display device with the alignment films 291 and 292including the main alignment films 33 and 34 having rigid verticalalignment side-chains is manufactured according to an exemplaryembodiment of the present invention. The surface alignment reactant 10having rigid vertical alignment side-chains includes, for example, acyclobutyl dianhydride of about 43 mol % as an alicyclicdianhydride-based monomer, a mono-methacrylic benzenediamine of about8.5 mol % as a photo-reactive diamine-based monomer, an octadecylcyclohexyl benzenediamine of about 6.5 mol % as an alkylated aromaticdiamine-based monomer, a diphenyl diamine of about 28 mol % as anaromatic diamine-based monomer, and an epoxy benzene derivative of about14 mol % as an aromatic epoxide-based monomer. Mol % of each componentis its mol % in the surface alignment reactant 10, and the solvent isnot involved in the composition ratio of the surface alignment reactant10.

The liquid crystal display panel assembly 300 was manufactured accordingto the just mentioned method. The structure of the pixels PX of theliquid crystal display device was substantially similar to the structureof those in FIG. 3. The cell spacing in the liquid crystal layer 3 was,for example, about 3.6 μm, the width of the micro branches 197 of thepixel electrode 191 was about the exposure voltage was about 7.5V, about10V, about 20V, about 30V and about 40V by the DC voltage supply, and UVintensity in the electric-field lithography process was about 7 J/cm²,about 9 J/cm², about 11 J/cm², about 12 J/cm² and about 15 J/cm². Themanufactured liquid crystal display device was operated by chargesharing-based 1G1D driving described above in conjunction with FIG. 11.

A response time of the manufactured liquid crystal display device was,for example, about 0.01 second to about 0.014 seconds, and a blackafterimage thereof showed a good level of approximately 2.

In accordance with an exemplary embodiment of the present invention, thesurface alignment reactant 10 forming the alignment films has, forexample, a compound in which a light hardener and a crosslinker arebonded. The surface alignment reactant 10 is formed, with the lighthardener bonded to the crosslinker, thus reducing the non-hardened lighthardener remaining in the process of manufacturing the liquid crystaldisplay panel assembly 300. The non-hardened light hardener increases anRDC in the liquid crystal display device, causing the afterimage defect.In accordance with an exemplary embodiment of the present invention, thealignment films manufactured by the surface alignment reactant 10 havinga compound of the light hardener and the crosslinker reduce theafterimage (or persistence) of the liquid crystal display device.

The current exemplary embodiment of the present invention issubstantially similar to the aforesaid method of manufacturing theliquid crystal display panel assembly 300 with the alignment films 291and 292 having negative electricity characteristics, except for thematerial constituting the surface alignment reactant 10 and that thecrosslinker bonded to the light hardener is linked to side chains of themain alignment film 33/34. Duplicate descriptions will be simplified oromitted.

Now, a detailed description will be made of a process of formingalignment films with a compound of a light hardener and a crosslinker.By the aforementioned methods corresponding thereto, the surfacealignment reactant 10 having a compound of the light hardener and thecrosslinker, is applied onto the lower display panel 100 with the pixelelectrode 191 and the upper display panel 200 with the common electrode270.

The compound of the light hardener and the crosslinker forms the surfacealignment reactant 10 by being mixed with the material forming the mainalignment film. The light hardener is chemically bonded to thecrosslinker, thus reducing the occurrence of ionic impurities. The lighthardener may be, for example, the aforementioned photo-reactive polymer,reactive mesogen, light hardener, photopolymerization material, orphoto-isomerization material, and the light hardener forms photohardening layers. The material forming the main alignment film may beone of the aforesaid materials for doing such, and it aligns the liquidcrystal molecules 31 in, for example, a direction perpendicular to thesurface of the substrates 110 and 210 or the pixel electrode 191.

Materials of a surface alignment reactant 10 including a compound ofwhich a light hardener and a crosslinker are linked to each other willbe described in detail below. A surface alignment reactant 10 includinga compound of which a light hardener and a crosslinker are linked toeach other according to an exemplary embodiment of the present inventionis, for example, a mixture in which polyimide-based compounds and acrosslinker are mixed with each other. Polyimide-based compound is acompound of which, for example, a dianhydride group monomer and adiamine group monomer are chemically linked with each other.Polyimide-based compound can be manufactured by, for example, imidationof a dianhydride group monomer and a monomer included in diamine groupmonomers as described above. Monomers constituting diamine groupmonomers, e.g., alkylated aromatic diamine group monomers and aromaticdiamine group monomers should be mixed, for example, prior to imidation.

A light hardener according to an exemplary embodiment of the presentinvention is, for example, a reactive mesogen. Therefore, a surfacealignment reactant 10 including a compound of which a reactive mesogenand a crosslinker are linked with each other may be a polymercomprising, for example, dianhydride group monomers (e.g., alicyclicdianhydride group monomers), diamine group monomers (e.g., alkylatedaromatic diamine group monomers and aromatic diamine group monomers),and a crosslinker (e.g., aromatic acryl-epoxide group monomers).Aromatic acryl-epoxide group monomers according to an exemplaryembodiment of the present invention are compounds of which a reactivemesogen and a crosslinker are linked with each other.

A surface alignment reactant 10 including a compound of which a reactivemesogen and a crosslinker are linked with each other is comprised of,for example, alicyclic diahydride group monomers of about 31 mol % toabout 41 mol % (e.g., about 36 mol %), alkylated aromatic diamine groupmonomers of about 3 mol % to about 9 mol % (e.g., about 6 mol %),aromatic diamine group monomers of about 25 mol % to about 35 mol %(e.g., about 30 mol %), and aromatic acryl epoxide group monomers ofabout 23 mol % to about 33 mol % (e.g., about 28 mol %). A mol %composition ratio of a surface alignment reactant 10 is mol % except fora solvent.

Alicyclic diahydride group monomers facilitate polymers included in asurface alignment reactant 10 to be dissolved in a solvent, and enableelectro-optic properties of an alignment film, for example, a VHR, to beincreased, and an RDC voltage to be decreased. A structure of alicyclicdiahydride group monomers may be, for example, a cyclobutyl dianhydridemonomer represented by formula XVI-RCA.

Alkylated aromatic diamine group monomers are, for example, monomers ofa vertical alignment component. The cyclic ring linked with benzenemakes a vertical alignment rigid. A cyclic ring may be, for example, aplate-type molecule. The structure of an alkylated aromatic diaminemonomer may be, for example, octadecyl cyclohexyl benzenediaminerepresented by formula XVIII-RCA1 or alkyl substituted aliphaticaromatic benzenediamine represented by formula XVIII-RCA2.

Aromatic diamine group monomers facilitate polymers included in asurface alignment reactant 10 to be dissolved in a solvent. Thestructure of aromatic diamine group monomers may be, for example,diphenyl diamine represented by formula VI-RCA as mentioned above.

Aromatic acryl-epoxide group monomers form a crosslinked structure toincrease heat resistance and chemical resistance, and are cured by UV toform a photo hardening layer having a pre-tilt angle. An aromaticacryl-epoxide group monomer is, for example, a compound of which anepoxy molecule which is a crosslinker and an acrylate molecule which isa light hardener are chemically linked with each other. As a lighthardener is linked with a crosslinker, the generation of ionicimpurities may decrease. The structure of an aromatic acryl-epoxidegroup monomer may be, for example, an acryl-epoxy hybrid benzenederivative represented by formula XIIIC.

where YC may be a phenyl derivative.

An acryl-epoxy hybrid benzene derivative can be manufactured by, forexample, mixing an epoxy substituted phenol derivative and a methacrylicchloride in a polar solvent to produce a mixture, and esterifying thismixture.

The aforesaid photoinitiator may be added to the surface alignmentreactant 10. Unlike the surface alignment reactant 10 having negativeelectricity characteristics, the surface alignment reactant 10 having acompound of a light hardener and a crosslinker may not have the polymerhaving negative electricity characteristics.

After being applied, the surface alignment reactant 10 having a compoundof a reactive mesogen and a crosslinker is, for example, primarilyheated by the aforementioned primary heating method. While beingprimarily heated, monomers of the reactive mesogen components and thevertical alignment components forming the main alignment film arealigned, for example, in perpendicular to the lower layer of 10. Duringthe primary heating, the surface alignment reactant 10 having a compoundof a reactive mesogen and a crosslinker may not undergo phase separationdescribed above in connection with FIG. 8C.

After undergoing the primary heating, the surface alignment reactant 10is secondarily heated by, for example, the aforementioned secondaryheating method. The solvent of the surface alignment reactant 10 is, forexample, vaporized by the secondary heating. In addition, thecrosslinker bonded to the reactive mesogen is linked to a side chain ofthe polymer forming the main alignment film. Therefore, side chains ofthe reactive mesogen are formed on the surface of the surface alignmentreactant 10.

After the secondary heating, the surface alignment reactant 10 is, forexample, cleaned and then dried by an aforementioned cleaning and dryingmethod. After the drying, a sealant is formed by one of theaforementioned sealing methods. As described above, the sealant may behardened in UV having a wavelength of about 300 nm to about 400 nm, orin light having a wavelength of about 400 nm or more. Thereafter, inaccordance with the aforementioned methods corresponding thereto, anupper-plate common voltage applying point (not shown) and a liquidcrystal layer are formed, and the lower and upper display panels 100 and200 are assembled. The sealant is hardened by light or heat as describedabove.

The assembled display panels are annealed by the aforementionedannealing methods, and provided with voltages by the DC voltage supplyor multi-step voltage supply of FIG. 7A or 7B. The process in which anelectric field is formed in the liquid crystal layer 3 is substantiallysimilar to the aforementioned process corresponding thereto. Unlike themethod of forming the alignment films having negative electricitycharacteristics, the vertically aligned reactive mesogen is aligned tobe tilted in the electric field through interaction with liquid crystalmolecules 31. While the liquid crystal molecules 31 and the reactivemesogens are aligned in a specific tilt angle by the supplied voltage,the electric-field lithography process is performed on the assembledliquid crystal display panel assembly 300 by the aforementioned fieldexposure method. An acrylate reactive group of the reactive mesogen ishardened by, for example, light to form a network among reactive mesogenmonomers. The reactive mesogen formed as a network forms the photohardening layers 35 and 36 having a pre-tilt angle on the main alignmentfilm 33/34. The photo hardening layer according to an exemplaryembodiment of the present invention, e.g., reactive mesogen, is bondedto the crosslinker, thus significantly reducing the non-hardenedreactive mesogen and the occurrence of ionic impurities. In addition,the combination of the reactive mesogen and the crosslinker reduces theionic impurities and the RDC, contributing to the increased afterimageof the liquid crystal display device.

Thereafter, the aforementioned fluorescent lithography process may beperformed.

By doing so, the surface alignment reactant 10 having a compound of areactive mesogen and a crosslinker forms the alignment films,manufacturing the liquid crystal display panel assembly 300. Thealignment films manufactured by the compound bonded to the crosslinkeraccording to an exemplary embodiment of the present invention can reducethe afterimage defect of the liquid crystal display panel.

In accordance with an exemplary embodiment of the present invention, thealignment films 291 and 292 formed by the surface alignment reactant 10having a compound of a reactive mesogen and a crosslinker weremanufactured, and the liquid crystal display device having them wasmanufactured. In accordance with an exemplary embodiment of the presentinvention, the surface alignment reactant 10 forming the alignment filmsincluded, for example, a cyclobutyl dianhydride of about 36 mol % as analicyclic dianhydride-based monomer, an octadecyl cyclohexylbenzenediamine of about 6 mol % as an alkylated aromatic diamine-basedmonomer, a diphenyl diamine of about 30 mol % as an aromaticdiamine-based monomer, and an acryl-epoxy hybrid benzene derivative ofabout 28 mol % as an aromatic acryl-epoxide-based monomer. Mol % of eachcomponent is its mol % in the surface alignment reactant 10, and thesolvent is not involved in the composition ratio of the surfacealignment reactant 10.

The liquid crystal display panel assembly 300 was manufactured accordingto the just mentioned method. The structure of the pixels PX of theliquid crystal display device was substantially similar to the structureof those in FIG. 3. The cell spacing in the liquid crystal layer 3 was,for example, about 3.6 μm, the width of the micro branches 197 of thepixel electrode 191 was about 3 μm, the exposure voltage was about 30V,about 40V and about 50V by the DC voltage supply, and UV intensity inthe electric-field lithography process was about 9 J/cm², about 12 J/cm²and about 17 J/cm². The manufactured liquid crystal display device wasoperated by charge sharing-based 1G1D driving described above inconjunction with FIG. 11.

The manufactured liquid crystal display device was operated, forexample, for about 336 hours, and its black afterimage showed a goodlevel of approximately 2 or less.

In accordance with another exemplary embodiment of the presentinvention, the surface alignment reactant 10 forming the alignment filmshas a compound, for example, in which an inorganic material and a lighthardener are bonded. In other words, the surface alignment reactant 10consisting of an inorganic material bonded to a light hardener is usedto form the alignment films.

Unlike the organic-based material, the inorganic material formingalignment films does not absorb ionic impurities in the liquid crystal,has small changes in physical properties, and is not oxidized or doesnot generate ionic impurities at a high temperature. Thus, the alignmentfilms formed by the inorganic material bonded to the light hardener maynot only have small changes in physical properties and a photo hardeninglayer having a stable pre-tilt angle, but may also reduce the afterimageand stains of the liquid crystal display device despite a long operatingtime and do not reduce a VHR. In addition, the inorganic material canform the alignment films even at a low temperature, making it possibleto select various materials forming a lower layer of the alignmentfilms. The inorganic material may be, for example, anorthosilicate-based monomer or a siloxane-based monomer. An alignmentfilm formed of the organic-based material reduces the VHR and generatesafterimages, stains and a DC voltage because a lot of non-imidizedcarboxy groups may absorb ionic impurities in the liquid crystal.Herein, ‘imidization’ refers to performing thermal cyclodehydration onpolyamic acid obtained by conducting condensation polymerization on thedianhydride and the aromatic diamine.

In accordance with an embodiment of the present invention, the inorganicmaterial may comprise, for example, silicon, aluminum, titanium, or thelike. The inorganic material may be, for example, silicon oxide (SiOx)such as SiO2 and SiO, or metal oxide such as MgO and ITO.

The current exemplary embodiment of the present invention issubstantially similar to the aforesaid method of manufacturing theliquid crystal display panel assembly 300 with the alignment films 291and 292 having negative electricity characteristics, except for thematerial constituting the surface alignment reactant 10 and thesecondary heating for forming the main alignment film 33/34. Duplicatedescriptions will be simplified or omitted.

The surface alignment reactant 10 having a compound of an inorganicmaterial and a light hardener is applied by the aforementioned methods(corresponding thereto) on the lower display panel 100 with the pixelelectrode 191 and the upper display panel 200 with the common electrode270. The inorganic material and the light hardener may be chemicallybonded. In accordance with an exemplary embodiment of the presentinvention, the surface alignment reactant 10 may be deposited on thepixel electrode 191 and the common electrode 270 by, for example, vapordeposition such as Chemical Vapor Deposition (CVD).

Materials of a surface alignment reactant 10 including a compound ofwhich inorganic-based materials and a crosslinker are linked with eachother will be described in detail below. According to an exemplaryembodiment of the present invention, a surface alignment reactant 10including a compound of which inorganic-based materials and acrosslinker are linked with each other is, for example, a compound ofwhich an alkyl alcohol group monomer and a vinyl alcohol group monomerincluded in orthosilicate group monomers and alkoxide group monomers arechemically linked with each other. A surface alignment reactant 10 canbe manufactured by, for example, mixing orthosilicate group monomers,alkyl alcohol and vinyl alcohol monomers in a polar solvent to produce amixture, stirring this mixture in H2O comprising acid or base catalystto liberate hydroxyl group from alkyl alcohol and vinyl alcohol, whichnucleophilic-attacks silicone atom of orthosilicate to performhydrolysis and condensation polymerization.

According to an exemplary embodiment of the present invention,inorganic-based materials are, for example, orthosilicate groupmonomers. Therefore, a surface alignment reactant 10 including acompound of which inorganic materials and a crosslinker are linked witheach other may be a polymer comprised of, for example, alkoxide groupmonomers of about 40 mol % to about 70 mol % (e.g., about 56 mol %),which comprise orthosilicate group monomers of about 30 mol % to about60 mol % (e.g., about 44 mol %) and a crosslinker. Orthosilicate groupmonomers may be, for example, tetraalkoxy orthosilicate monomers.Alkoxide group monomers may be comprised of, for example, monomerscomprising alkyl alcohol group monomers of about 1 mol % to about 10 mol% (e.g., about 6 mol %) and a crosslinker of about 40 mol % to about 60mol % (e.g., about 50 mol %). A mol % composition ratio of eachcomponent in a surface alignment reactant 10 is mol % except for asolvent. Monomers including a light hardener according to the presentinvention may be at least one selected from, for example, vinyl alcoholgroup monomers, acryl group monomers, cinnamoyl group monomers andmixtures or combinations thereof.

Orthosilicate group monomers form a main chain of the main alignmentfilm, facilitate monomers included in a surface alignment reactant 10 tobe dissolved in a solvent, and increase electro-optic properties of thealignment film, for example, VHR. Orthosilicate group monomers accordingto an exemplary embodiment of the present invention may be, for example,tetraalkoxy orthosilicate group monomers. The structure of a tetraalkoxyorthosilicate group monomer may include, for example, a tetraethylorthosilicate monomer represented by formula XIX-T1, an alkyl groupmonomer, or hydroxyl group monomer.

Orthosilicate group monomers according to the present invention may be apolysiloxane group polymer manufactured by, for example, polymerizingsilane compounds, or polymerizing alkoxy silane compounds.

Alkyl alcohol group monomers are a monomer of vertical alignmentcomponent connected with a side chain of orthosilicate group polymersforming a main chain. Therefore, alkyl alcohol group monomer maycomprise, for example, long alkyl-based polymers. The structure of alkylalcohol group monomers may be, for example, a dodecanol monomerrepresented by following formula XIX-A1, a cholesteric group monomerrepresented by formula XIX-A2, an alkylated alicyclic group monomerrepresented by formula XIX-A3, an alkylated aromatic group monomerrepresented by formula XIX-A4 or an alkyl group monomer.

Vinyl alcohol group monomers are, for example, a vinyl group monomerwhich is cured by UV to form a photo hardening layer having a pre-tiltangle. Vinyl alcohol group monomers are connected with a side chain oforthosilicate-based polymer forming a main chain. The structure of avinyl alcohol group monomer may be, for example, a hydroxyalkyl acrylatemonomer represented by formula XIX-V1 or an alkylated vinyl groupmonomer represented by formula XIX-V2.

where XV may be alkyl, ether or ester, and YV may be methyl or hydrogen.Cinnamoyl group monomers are connected with a side chain oforthosilicate-based polymer forming a main chain, and are cured by UV toform a photo hardening layer having a pre-tilt angle. A hydroxyalkylacrylate monomer can be manufactured by mixing alkanediol and acrylicchloride in a polar solvent to produce a mixture, and esterifying thismixture.

The structure of a cinnamoyl group monomer may be, for example, analkylated cinnamoyl group monomer represented by formula XIX-C1.

where XC may be any one selected from alkyl, ether, ester, phenyl,cyclohexyl, and ester-phenyl. YC may be any one selected from alkyl,phenyl, biphenyl, cyclohexyl, bicyclohexyl, and phenyl-cyclohexyl. Alight hardener may be the above-described photo-reactive polymer,reactive mesogen, light hardener, photo-polymerizable material orphoto-isomerizable material. A photo initiator mentioned above may beadded to a surface alignment reactant 10 including a compound of whichinorganic-based materials and a light hardener are linked with eachother.

The applied surface alignment reactant 10 having a compound of aninorganic material and a light hardener is primarily heated by, forexample, the aforementioned primary heating method. While beingprimarily heated, the alkyl alcohol-based molecules of verticalalignment components linked to side chains of the orthosilicate-basedmonomer and the light hardener forming the photo hardening layers 35 and36 are, for example, aligned in perpendicular to the lower layer of 10.During the primary heating, the applied surface alignment reactant 10having a compound of an inorganic material and a light hardener may notundergo phase separation as described above in connection with FIG. 8C.

After undergoing the primary heating, the surface alignment reactant 10is, for example, secondarily heated at a temperature lower than theaforementioned secondary heating temperature, e.g., at about 150° C. toabout 200° C. (e.g., about 180° C.). The secondary heating may beperformed, for example, for about 1000 seconds to about 1400 seconds(e.g., about 1200 seconds). Because of the low secondary heatingtemperature, the material constituting the lower layer of the surfacealignment reactant 10 may be selected from a wide range of materials. Acolor filter material formed on the bottom of the surface alignmentreactant 10 according to an exemplary embodiment of the presentinvention may be, for example, a dye that can be processed at a lowtemperature. During the secondary heating, the solvent of the surfacealignment reactant 10 is, for example, vaporized, and theorthosilicate-based monomer constituting the main chain and the alkylalcohol-based monomer of vertical alignment components linked to sidechain, form the main alignment film 33/34. The main alignment film 33/34formed by the surface alignment reactant 10 having a compound of aninorganic material and a light hardener, does not absorb ionicimpurities, and is not oxidized or does not generate ionic impurities ata high temperature, thus reducing afterimages and stains of the liquidcrystal display device and increasing a VHR.

After the secondary heating, the surface alignment reactant 10 having acompound of an inorganic material and a light hardener is, for example,cleaned and dried by an aforementioned cleaning and drying method. Thesurface alignment reactant 10 according to an exemplary embodiment ofthe present invention is not deteriorated in material properties by thecleaning or drying process.

After the drying, a sealant is formed by one of the aforementionedsealing methods. As described above, the sealant may be hardened in UVhaving a wavelength of about 300 nm to about 400 nm, or in light havinga wavelength of about 400 nm or more. Next, in accordance with theaforementioned methods corresponding thereto, an upper-plate commonvoltage applying point (not shown) and a liquid crystal layer areformed, and the lower and upper display panels 100 and 200 areassembled. The sealant is hardened by light or heat as described above.

The assembled display panels are annealed by one of the aforementionedannealing methods, and provided with voltages by the DC voltage supplyor multi-step voltage supply of FIGS. 7A and 7B. The process in which anelectric field is formed in the liquid crystal layer is substantiallysimilar to the aforementioned electric-field forming process. Unlike themethod of forming the alignment films having negative electricitycharacteristics, the vertically aligned light hardener or reactivemesogen is aligned, for example, to be tilted in the electric fieldthrough interaction with liquid crystal molecules 31. While the liquidcrystal molecules and the reactive mesogens are aligned in a specifictilt angle by the supplied voltage, the electric-field lithographyprocess is performed on the assembled liquid crystal display panelassembly by an aforementioned field exposure method. The UV intensity inthe electric-field lithography process may be, for example, about 6J/cm² to about 20 J/cm² (e.g, about 12 J/cm²).

An acrylate reactive group of the reactive mesogen is, for example,hardened by light to form a network among reactive mesogen monomers. Thereactive mesogen formed as a network forms the photo hardening layers 35and 36 having a pre-tilt angle on the main alignment film 33/34. Themain alignment film 33/34 and the photo hardening layer 35/36 formed inthe pre-process form the alignment film. The photo hardening layer 35/36formed by the surface alignment reactant 10 having a compound of aninorganic material and a light hardener shows excellent reliability andstability because of the combination with the inorganic material.

Thereafter, the aforementioned fluorescence lithography process may beperformed.

By doing so, the surface alignment reactant 10 having a compound of aninorganic material and a light hardener, forms the alignment filmsconsisting of the main alignment films 33 and 34 and the photo hardeninglayers 35 and 36, thereby manufacturing the liquid crystal display panelassembly 300 having the alignment films.

In accordance with an exemplary embodiment of the present invention, thealignment films formed by the surface alignment reactant 10 having acompound of an inorganic material and a light hardener have photohardening layers having a stable pre-tilt angle, and the alignment filmsshow excellent thermal resistance, long-term reliability, chemicalresistance, and uniformity. In addition, the surface alignment reactant10 having a compound of an inorganic material and a light hardener mayreduce the time for manufacturing the liquid crystal display device, asit needs no additional process because of its excellent electrostaticelimination properties.

In accordance with an exemplary embodiment of the present invention, thealignment films 291 and 292 formed by the surface alignment reactant 10having a compound of an inorganic material and a light hardener weremanufactured, and the liquid crystal display device having them wasmanufactured. In accordance with an exemplary embodiment of the presentinvention, the surface alignment reactant 10 forming the alignment filmsincluded, for example, a tetraalkoxy orthosilicate-based monomer ofabout 44 mol % as a tetraalkoxy orthosilicate-based monomer, adodecanol-based monomer of about 6 mol % as an alkyl alcohol-basedmonomer, and a hybroxyalkyl acrylate-based monomer of about 50 mol % asa vinyl alcohol-based monomer. Mol % of each component is for thesurface alignment reactant 10, with a solvent excluded.

The liquid crystal display panel assembly 300 was manufactured accordingto the just mentioned method. The structure of the pixels PX of theliquid crystal display device was substantially similar to the structureof those in FIG. 3. The cell spacing in the liquid crystal layer 3 was,for example, about 3.6 μm, the width of the micro branches 197 of thepixel electrode 191 was about 4 μm, the exposure voltage was about 20Vor about 24V by the DC voltage supply, and UV intensity in theelectric-field lithography process was about 5 J/cm², about 10 J/cm²,and about 20 J/cm². The manufactured liquid crystal display device wasoperated by charge sharing-based 1G1D driving described above inconjunction with FIG. 11.

In the manufactured liquid crystal display device, the VHR was, forexample, about 90.5% or more, the ion density was about 5 pC/cm² orless, and the black afterimage showed a good level of about 2.5 in a168-hour operation.

In accordance with an exemplary embodiment of the present invention, thesurface alignment reactant 10 forming an alignment film is, for example,a mixture of inorganic materials in which functional groups are bonded.The alignment film including an inorganic material may have an excellentadhesion with the lower layer, a low adhesion with ionic impuritiesexisting the liquid crystal layer, and a high reliability when used inan oxidizing atmosphere at a high temperature for a long time.

First, a surface alignment reactant 10 manufactured by mixing inorganicgroup compounds linked with functional groups will be described indetail. A surface alignment reactant 10 mixed with inorganic-basedcompounds is a mixture of the first surface alignment compounds (notshown) comprising the first inorganic material and the second surfacealignment compounds (not shown) comprising the second inorganic-basedmaterials. According to the present invention, the first inorganic-basedmaterials and the second inorganic-based materials may be, for example,a siloxane. The first surface alignment compound may have a functionalgroup which increases the reliability and the physical property of analignment film. The second surface alignment compound may have variousfunctional groups which aligns liquid crystal molecules. Functionalgroups will be described below. A solvent used to mix the first surfacealignment compound and the second surface alignment compound may be, forexample, hexylene glycol (HG), butyl cellosolve (BCS), 1,3-butanediol(1,3-BD) or propylene glycol monobutyl ether. A solvent may be any ofmaterials other than the above-described materials which can dissolvethe first surface alignment compound and the second surface alignmentcompound. The sum of the first surface alignment compound and the secondsurface alignment compound included in a surface alignment reactant 10may be, for example, about 2 wt % to about 4 wt %, and a solvent may beabout 96 wt % to about 98 wt %. According to the present invention, thefirst surface alignment compound and the second surface alignmentcompound may be mixed in, for example, a weight ratio of about 6˜about 8to about 2˜about 4 (e.g., in a weight ratio of about 7 to about 3). Asolvent is not included in the weight ratio. According to an exemplaryembodiment of the present invention, a solvent included in a surfacealignment reactant 10 comprises, for example, hexylene glycol (HG) ofabout 45 wt % to about 65 wt %, butyl cellosolve (BCS) of about 10 wt %to about 30 wt %, and propylene glycol monobutyl ether of about 15 wt %to about 35 wt %. According to an exemplary embodiment of the presentinvention, a solvent included in a surface alignment reactant 10comprises, for example, hexylene glycol (HG) of about 25 wt % to about45 wt %, butyl cellosolve (BCS) of about 8 wt % to about 28 wt %,1,3-butane diol (1,3-BD) of about 3 wt % to about 11 wt %, and propyleneglycol monobutyl ether of about 30 wt % to about 50 wt %. According toan exemplary embodiment of the present invention, a surface alignmentreactant 10 may comprise, for example, the first surface alignmentcompound of about 2.1 wt %, the second surface alignment compound ofabout 0.9 wt %, hexylene glycol of about 65 wt %, butyl cellosolve ofabout 30 wt %, and 1,3-butane diol of about 5 wt %. As the surfacealignment reactant 10 includes the first surface alignment compound andthe second surface alignment compound in a mixture, it may be readilyphase-separated into a material comprising a first surface alignmentcompound and a material comprising a second surface alignment compoundin a process of forming an alignment film.

According to the present invention, the first surface alignment compoundcomprises, for example, a compound of the following formula IM1. Acompound of the following formula IM1 is a compound in which siloxanegroup monomer which is a kind of inorganic-based materials, and IM-R6functional group are linked to each other. The first surface alignmentcompound can be stably linked with a lower layer. As the first surfacealignment compound has a feature of inorganic materials, alignment films291 and 292 comprising the first surface alignment compound may havegood reliability. As the first surface alignment compound comprises anequal polarity (e.g., hydrophilicity or hydrophobicity) to that of alower layer, it can be readily phase-separated from the second surfacealignment compound having a different polarity in a heating processdescribed below. IM-R6 functional group included in the first surfacealignment compound may substantially have the hydrophilic features.

In the above formula IM1, IM-R6 may comprise alkyl group monomers orhydroxyl group monomers. An alkyl group monomer may comprise about 0 toabout 5 carbon atoms.

According to an exemplary embodiment of the present invention, the firstsurface alignment compound can be synthesized, for example, as in thefollowing reaction formula IM1-M1. The first surface alignment compoundcan be manufactured by, for example, mixing tetraethyl orthosilicate ina polar solvent (tetrahydrofuran, THF) to produce a mixture, andstirring this mixture in water (H2O) comprising acid (for example,hydrochloric acid, HCl) or base catalyst.

The second surface alignment compound will be described in detail below.According to the present invention, the second surface alignmentcompound comprises, for example, the following formula IM2. Formula IM2is a structure in which a siloxane group monomer which is a kind ofinorganic-based material, and IM-T1, IM-T2 and IM-T3 functional groupsare linked to each other. IM-T1, IM-T2 and IM-T3 functional groups areeach linked to a siloxane group monomer constituting a main chain toform a side chain.

IM-T1 functional group is a vertical functional group which canvertically align liquid crystal molecules with respect to a lower layer.IM-T1 functional group can interact with liquid crystal molecules. IM-T2functional group can be polymerized by, for example, light (e.g., UV) orheat. IM-T2 functional groups are a pre-tilt functional group which canbe cross-linked, or polymerized or cured to align liquid crystalmolecules to be tilted. IM-T3 functional groups are a functional groupwhich can increase the reliability of the alignment film which is formedby the second surface alignment compound, and enhance physicalproperties. The second surface alignment compound comprises, forexample, IM-T1 functional group of about 5 mol % to about 15 mol % (e.g.about 10 mol %), IM-T2 functional group of about 40 mol % to about 60mol % (e.g., about 50 mol %), and IM-T3 functional group of about 30 mol% to about 50 mol % (e.g., about 40 mol %). A mol % of respectivefunctional group is a mol % in the second surface alignment compoundexcept for siloxane and a solvent. The second surface alignment compoundcomprising these various functional groups can be readilyphase-separated in a process of forming alignment films. As variousfunctional groups can align liquid crystal molecules to be perpendicularto or tilted with respect to a lower layer, they can increase thecharacteristics of a liquid crystal display device. IM-T1 and IM-T2functional groups included in the second surface alignment compound can,for example, substantially have hydrophobic features. The second surfacealignment compound may comprise, for example, the photo initiatordescribed above.

IM-T1 functional group may comprise, for example, a monomer of thevertical alignment component which vertically aligns liquid crystalmolecules of a liquid crystal layer. IM-T1 functional group maycomprise, for example, monomers represented by the above-mentionedformulas XIX-A, XIX-A2, XIX-A3 and XIX-A4. IM-T1 functional group maycomprise, for example, an alkyl alcohol group monomer having about 5 to20 carbon atoms.

IM-T2 functional group may be, for example, polymerized and cross-linkedby light (e.g., UV) or heat energy in a process of forming alignmentfilms, to form a photo hardening layer having a pre-tilt angle. IM-T2functional group may comprise, for example, a vinyl group, an acrylicgroup, an acrylate group, a cinnamate group or a methacrylate group. Thevinyl group or the acrylic group may include, for example, aliphaticalkyl group having 1 to 18 carbon atoms. IM-T2 functional group maycomprise, for example, monomers represented by the above-mentionedformulas XIX-V1, XIX-V2 and XIX-C1. According to an exemplary embodimentof the present invention, IM-T2 functional group may comprise, forexample, the above-mentioned photo-reactive polymer, reactive mesogen,light hardener, photo-polymerizable material or photo-isomerizablematerial.

IM-T3 functional group may include, for example, materials describedabove with reference to IM-R6.

According to an exemplary embodiment of the present invention, thesecond surface alignment compound can be, for example, synthesized as inthe following reaction formula IM2-M1. The second surface alignmentcompound can be formed by, for example, mixing tetraethyl orthosilicatein a polar solvent (tetrahydrofuran, THF) to produce a mixture, andstirring this mixture together with long alkyl and alkylated acrylate,in water (H2O) comprising acid (e.g., hydrochloric acid, HCl) or basecatalyst. The long alkyl group can serve as IM-T1 functional group.Acrylate group can serve as IM-T2 functional group. The second surfacealignment compound can be manufactured by, for example, nucleophilichydrolysis and condensation polymerization.

A process of manufacturing the alignment films 291 and 292 and theliquid crystal display panel assembly 300 using the aforesaid surfacealignment reactant 10 manufactured by mixing the inorganic-basedcompounds in which functional groups are bonded will now be described indetail. This surface alignment reactant 10 includes, for example, thefirst surface alignment compound for increasing the reliability and thematerial properties of the alignment film, and the second surfacealignment compound having functional groups for aligning the liquidcrystal molecules. The surface alignment reactant 10, in which theinorganic-based compounds are mixed, may form the alignment film of theliquid crystal display panel assembly 300 substantially by the SC-VAmode-based method. A method of forming the alignment films 291 and 292will be described in detail with reference to FIGS. 8A to 8E. Duplicatedescriptions will be simplified or omitted. Differences between theSC-VA mode-based method and the method of forming the alignment filmaccording to an exemplary embodiment of the present invention will nowbe described in detail.

The lower display panel 100 with the pixel electrode 191 and the upperdisplay panel 200 with the common electrode 270 are manufactured in theabove/below-described methods. A method of forming the alignment filmusing the above-described surface alignment reactant 10 manufactured bymixing the inorganic-based compounds in which functional groups arebonded will now be described in detail. To avoid duplicate descriptions,the method of forming the upper-plate alignment film 292 will beomitted, and only the method of forming the lower-plate alignment film291 will be described.

Referring to FIG. 8A, the surface alignment reactant 10 manufactured bymixing the inorganic-based compounds in which functional groups arebonded, is formed on the pixel electrode 191 by the above-describedmethods.

Referring to FIG. 8B, the surface alignment reactant 10 including thefirst and second surface alignment compounds is, for example, primarilyheated in the aforesaid method. In the primary heating process, thesolvent of the surface alignment reactant 10 may be removed.

Referring to FIG. 8C, the surface alignment reactant 10 isphase-separated into a surface inorganic layer 33 a and a surfacefunctional group layer 35 a. The surface inorganic layer 33 a is a layerin contact with the pixel electrode 191, while the surface functionalgroup layer 35 a is a layer in contact with the air. As the surfacealignment reactant 10 is phase-separated, the surface inorganic layer 33a may substantially include the first surface alignment compound whilethe surface functional group layer 35 a may substantially include thesecond surface alignment compound. In the primary heating process,siloxanes included in the surface inorganic layer 33 a and the surfacefunctional group layer 35 a are bonded, forming polysiloxanes. Thepolysiloxanes form the main chains in the surface inorganic layer 33 aand the surface functional group layer 35 a. The functional groups IM-T1included in the surface functional group layer 35 a are disposed incontact with the air, and may be, for example, arranged perpendicularlyto the surface of the substrate or the pixel electrode 191. Thefunctional groups IM-T2 included in the surface functional group layer35 a may be disposed in contact with the air. The first surfacealignment compound may have, for example, hydrophilic properties, whilethe second surface alignment compound may have, for example, hydrophobicproperties. Each of the first and second surface alignment compounds mayinclude, for example, the aforesaid materials.

Referring to FIGS. 8D and 8E, the phase-separated surface inorganiclayer 33 a and surface functional group layer 35 a are secondarilyheated in the aforesaid method. In the secondary heating process, thephase-separated surface inorganic layer 33 a and surface functionalgroup layer 35 a are hardened. The polysiloxanes included in the surfaceinorganic layer 33 a and the surface functional group layer 35 aadditionally undergo cross-linking, forming a stable matrix. By thesecondary heating process, the surface inorganic layer 33 a forms asurface inorganic alignment film 33. The polysiloxanes included in thesurface inorganic layer 33 a may be cross-linked to the polysiloxanesincluded in the surface functional group layer 35 a. In the secondaryheating process, hydroxyl ions remaining in the surface inorganic layer33 a and the surface functional group layer 35 a may be removed. In anexemplary embodiment of the present invention, reference numerals 33 a,33 and 35 a are used to indicate different names, e.g., the surfaceinorganic layer 33 a, the surface inorganic alignment film 33, and thesurface functional group layer 35 a, because they have partiallydifferent functions from those of the surface main alignment materiallayer 33 a, the main alignment film 33, and the surface light hardenerlayer 35 a. In an embodiment of the present invention, the primaryheating process may be omitted, and the reactions described above withreference to the primary and secondary heating processes may occur inthe secondary heating process.

Thereafter, for example, the surface inorganic alignment film 33 or thesurface functional group layer 35 a are cleaned by DIW, and may befurther cleaned by IPA. After the cleaning, the surface inorganicalignment film 33 or the surface functional group layer 35 a is dried.

In step S240, as described above, the sealant, the upper-plate commonvoltage applying point, and the liquid crystal layer 3 are formed, andthe lower display panel 100 and the upper display panel 200 areassembled. The assembled lower and upper display panels 100 and 200 maybe annealed in the aforesaid method.

In step S250, an exposure voltage is applied and light is irradiated tothe assembled lower and upper display panels 100 and 200, forming asurface functional hardening layer 35. The surface inorganic alignmentfilm 33 and the surface functional hardening layer 35 form thelower-plate alignment film 291. A surface inorganic alignment film 34and the surface functional hardening layer 36 included in theupper-plate alignment film 292 may be formed in theabove/below-described methods.

A method of forming the surface functional hardening layer 35 will bedescribed in detail below with reference to step S250. In step S252, anelectric field is applied to the liquid crystal layer 3. The electricfield may be formed in the liquid crystal layer 3 in the methodsdescribed with reference to step S152. In step S254, an electric-fieldlithography process is performed, in which light is irradiated to theassembled lower and upper display panels 100 and 200 while an electricfield is formed in the liquid crystal layer 3. The electric-fieldlithography process may be performed in the aforesaid method.

By the electric-field lithography process, the functional groups IM-T2included in the surface functional group layer 35 a are cured. The curedfunctional groups IM-T2 may form the surface functional hardening layer35. The functional groups IM-T2 are cured to be tilted in, for example,the substantially same direction as that of their near liquid crystalmolecules 31 by the incident UV in the method described above withreference to FIGS. 9A and 9B. The functional groups IM-T2 may form, forexample, a network in which they are bonded to each other, by undergoingpolymerization. For example, a double bond of alkenes included in thefunctional groups IM-T2 may be unfastened by UV, making it possible forthe functional groups IM-T2 to form the network or to undergocross-linking by being bonded to their adjacent functional groups IM-T2.The liquid crystal molecules 31 adjacent to the functional groups IM-T2may be arranged at a substantially constant pre-tilt angle by thehardened functional groups IM-T2. The liquid crystal molecules 31 may benormally arranged at the substantially constant pre-tilt angle when anelectric field is not applied to the liquid crystal layer 3 as describedabove. An average of the pre-tilt angles of the liquid crystal molecules31 may correspond to the pre-tilt angle of, for example, the photohardening layer. The pre-tilt angle may coincide with, for example, thetilt direction being parallel to the longitudinal direction of the microbranches 197 of the pixel electrode 191. The hardened functional groupsIM-T2, the functional groups IM-T1 and the functional groups IM-T3 maybe linked to the side chains of the polysiloxanes formed by thesiloxanes included in the surface functional group layer 35 a. Theaforementioned fluorescent lithography process may be optional. Thepolysiloxanes formed by performing the primary and secondary heating onthe second surface alignment compound may be formed on the polysiloxanesformed by the first surface alignment compound. Likewise, thefluorescent lithography process may be optional. The upper-plate surfacefunctional hardening layer 36 may be formed by the method of forming thelower-plate surface functional hardening layer 35.

The liquid crystal display panel assembly 300 having the surfacealignment reactant 10 manufactured by mixing inorganic-based compoundsin which functional groups are bonded, may have the characteristics ofthe SC-VA mode. The surface alignment reactant 10 may be readilyphase-separated in the process of forming the alignment films 291 and292, because it is a mixture of compounds bonded to the inorganicmaterials. Because the polymers that align the liquid crystal moleculesvertically or at a pre-tilt angle are bonded to the inorganic materials,the manufactured liquid crystal display device may have a high VHR,thereby preventing the display quality of the liquid crystal displaydevice from deteriorating due to the ionic impurities. Because theinorganic materials and the polymers having various functional groupsare bonded (e.g., the second surface alignment compound), the process ofeliminating the electrostatics is optional in the process of forming thealignment film, thereby simplifying the method of manufacturing theliquid crystal display device.

The surface alignment reactant 10 forming the alignment film accordingto an exemplary embodiment of the present invention has, for example,two or more light hardeners whose chain lengths are different. Thesurface alignment reactant 10 includes, for example, light hardenershaving different chain lengths, thus increasing a cross-linking rate ofthe light hardeners.

Materials of the surface alignment reactant 10 including light hardenershaving different chain lengths will now be described in detail. Thesurface alignment reactant 10 including light hardeners having differentchain lengths is, for example, a mixture of a third surface alignmentcompound and a fourth surface alignment compound. The surface alignmentreactant 10 may be readily phase-separated in the process of forming thealignment film because it is a mixture of surface alignment compounds.The third surface alignment compound may increase the reliability andthe material properties of the alignment film, like the first surfacealignment compound. The fourth surface alignment compound includesvarious functional groups that align the liquid crystal molecules. Thefourth surface alignment compound includes, for example, two differenttypes of light hardeners having different chain lengths, as pre-tiltingfunctional groups included in the second surface alignment compound. Thelight hardeners having different chain lengths may increase theircross-linking rate in the process of forming the alignment film.

According to an exemplary embodiment of the present invention, the thirdsurface alignment compound and the fourth surface alignment compoundincluded in a surface alignment reactant 10 may be mixed, for example,in a weight ratio of about 6˜about 8 to about 2˜about 4 (e.g, about 7 toabout 3). A solvent is not included in the weight ratio. The thirdsurface alignment compound, the fourth surface alignment compound and asolvent may be included in a surface alignment reactant 10 in the ratiodescribed above with reference to the first surface alignment compoundand the second surface alignment compound. In a mixing ratio ofingredients, the first surface alignment compound may be replaced withthe third surface alignment compound, and the second surface alignmentcompound may be replaced with the fourth surface alignment compound. Asolvent may be the solvent described above together with materials of asurface alignment reactant 10 formed by mixing compounds includinginorganic-based materials. According to an exemplary embodiment of thepresent invention, the third surface alignment compound includes, forexample, the formula IM1 described above or the following formula IM3. Asiloxane group monomer which forms a main chain and IM-R6 and IM-M6functional groups which form a side chain are linked together to formformula IM3. The third surface alignment compound having formula IM3 ofsiloxane group monomer can stably link with the layer formed in lowerpart. The third surface alignment compound may comprise, for example,IM-M6 functional group of about 5 mol % to about 15 mol % (e.g., about10 mol %), and IM-R6 functional group of about 80 mol % to about 95 mol% (e.g., about 90 mol %). A mol % of each functional group is a mol % inthe third surface alignment compound except for siloxane and a solvent.IM-M6 functional group may be a phase separation enhancer. A phaseseparation enhancer may inhibit the material included in the thirdsurface alignment compound, for example, silicone, from linking with thematerial included in the fourth surface alignment compound, for example,silicone in their mixtures to facilitate the phase separation. IM-M6functional group can decrease the density of a surface inorganicalignment film formed by the third surface alignment compound,facilitating rework of an alignment film. As the density of a surfaceinorganic alignment film is lower, a solvent used to rework thealignment film may more readily penetrate into a surface inorganicalignment film. IM-M6 functional group may include, for example, amethyl group. IM-R6 functional group has been described above withreference to the formula IM1. IM-M6 and IM-R6 functional groups includedin the third surface alignment compound may have, for example,hydrophilic properties.

According to an exemplary embodiment of the present invention, the thirdsurface alignment compound can be synthesized as in the followingreaction formula IM1-M3. The third surface alignment compound can bemanufactured by, for example, mixing tetraethyl orthosilicate in a polarsolvent (tetrahydrofuran, THF) to produce a mixture, and stirring thismixture with methyl group in water (H₂O) comprising acid (e.g.,hydrochloric acid, HCl) or base catalyst.

The fourth surface alignment compound will be described in detail below.The fourth surface alignment compound includes, for example, twofunctional groups (e.g., hardeners) which are cured by light or heat.Two functional groups having, for example, a curing property havedifferent chain lengths. Two functional groups which are cured cansubstantially serve as the pre-tilt functional group as mentioned abovewith reference to the second surface alignment compound. As pre-tiltfunctional groups included in the fourth surface alignment compound havedifferent chain lengths, the density and the cross-linking rate of thepre-tilt functional groups included in the fourth surface alignmentcompound can be increased. If the cross-linking rate of hardeners orpre-tilt functional groups increases, the display quality of a liquidcrystal display device can be increased.

According to the present invention, the fourth surface alignmentcompound includes the following formula IM4. A siloxane group monomerwhich forms a main chain and IM-T1, IM-T2, IM-T21 and IM-T3 functionalgroups which form a side chain are linked together to form formula IM4.The fourth surface alignment compound may comprise IM-T1 functionalgroup of about 5 mol % to about 15 mol % (e.g, about 10 mol %), IM-T2functional group of about 30 mol % to about 50 mol % (e.g, about 40 mol%), IM-T21 functional group of about 5 mol % to about 15 mol % (e.g.,about 10 mol %), and IM-T3 functional group of about 30 mol % to about50 mol % (e.g., about 40 mol %). A mol % of each functional group is amol % in the fourth surface alignment compound except for siloxane and asolvent. IM-T1, IM-T2 and IM-T21 functional groups included in thefourth surface alignment compound may substantially have, for example,the hydrophobic property.

IM-T1, IM-T2 and IM-T3 functional groups have been described above withreference to formula IM2. IM-T21 functional group is a pre-tiltfunctional group which can be, for example, polymerized or crosslinkedby light (e.g., UV) or heat. IM-T21 functional group can form a photohardening layer having a pre-tilt angle in a process of forming analignment film in the same way as IM-T2 described above. IM-T21functional group may comprise, for example, vinyl group, styrene group,methacrylate group, cinnamate group or acrylic group. IM-T21 functionalgroup may comprise monomers represented by above-mentioned formulasXIX-V1, XIX-V2 and XIX-C1. IM-T21 functional group may be, for example,the above-described photo-reactive polymer, reactive mesogen, lighthardener, photo-polymerizable material or photo-isomerizable material.According to an exemplary embodiment of the present invention, the mol %composition ratio of IM-T2 functional group to IM-T21 functional group,each having features of pre-tilt functional groups included in thefourth surface alignment compound, may be, for example, about 2˜about 10to 1. According to an exemplary embodiment of the present invention, themol % composition ratio of IM-T2 functional group to IM-T21 functionalgroup, each having features of vertical functional groups included inthe fourth surface alignment compound, may be, for example, about1˜about 3 to about 1˜about 3. According to an exemplary embodiment ofthe present invention, the mol % composition ratio of IM-T1 functionalgroup having a vertical functional group feature, to IM-T2 functionalgroup having a pre-tilt functional group feature, to IM-T21 having apre-tilt functional group feature, which are included in the fourthsurface alignment, to a phase enhancer included in the third surfacealignment compound is, for example, about 1˜about 3 to about 2˜about 10to about 1˜about 3 to about 1˜about 3.

The fourth surface alignment compounds may include a catalyst such as,for example, amine, or comprise a photo-initiator such as thiol group.The concentration of a catalyst or a photo-initiator included in thefourth surface alignment compound may be, for example, about 1 mol % toabout 7 mol %. A mol % of a catalyst or a photo-initiator is a mol % inthe fourth surface alignment compound except for siloxane and a solvent.According to an exemplary embodiment of the present invention, aphoto-initiator included in the fourth surface alignment compound maybe, for example, an alkylated thiol group having 1 to 5 carbon atoms. Aphoto-initiator may be linked with a side chain of siloxane groupmonomer. A photo-initiator can increase the curing of IM-T2 functionalgroup and IM-T21 functional group. As a photo-initiator reacts with aresidual radical generated from a material such as an insulation layerto decrease the radical, the quality of a liquid crystal display devicecan be increased. According to an exemplary embodiment of the presentinvention, a catalyst included in the fourth surface alignment compoundmay be, for example, an alkylated amine group having 1 to 5 carbonatoms. In the secondary heating procedure described below, a catalystcan increase the number of cross-linked bonds of polysiloxane. Acatalyst can, for example, be bonded to a side chain of siloxane groupmonomer. For example, a catalyst is a material which has no polarity. Amaterial with polarity collects impurities, causing degradation in theimage quality of a liquid crystal display device.

IM-T2 functional group and IM-T21 functional group according to anexemplary embodiment of the present invention will be described indetail below. IM-T2 functional group and IM-T21 functional groupcomprise, for example, a curing agent. According to an exemplaryembodiment of the present invention, the chain length of IM-T2functional group is, for example, different from that of IM-T21. A chainlength of IM-T2 functional group may be, for example, longer than thatof IM-T21. As the chain length of IM-T21 functional group is shorterthan that of IM-T2, the density of functional groups which arepolymerizable or crosslinkable or hardeners can be increased. In theprocess of performing a polymerization or crosslinking by light or heat,as IM-T21 functional groups placed between IM-T2 functional groupsincrease the degree of polymerization or crosslinking, the cross-linkingrate of a curing agent, e.g., IM-T2 functional group or IM-T21functional group can be increased. The chain length is the sum of thelength of bonds linked in the shortest distance from alkene included inIM-T21 functional group to main chain. In counting the chain length, itis assumed that the bonding length between atoms is equal. For example,it is assumed that the bonding length between carbon atoms, the bondinglength between carbon atom and oxygen atom, and the bonding lengthbetween carbon atom and silicone atom are equal. According to anexemplary embodiment of the present invention, the chain length of IM-T2functional group is, for example, longer about 3 to about 7 times thanthat of IM-T21 functional group. If the chain length of IM-T2 exceedsabout 7 times that of IM-T21, the force for aligning liquid crystalmolecules is decreased to make the alignment of liquid crystal moleculesnon-uniform. Non-uniformities of liquid crystal molecules candeteriorate the image quality of a liquid crystal display device.

According to an exemplary embodiment of the present invention, thebonding number of IM-T2 functional group is different from that ofIM-T21. The bonding number of IM-T2 may be, for example, larger thanthat of IM-T21. A bonding number is the number of bonds linked in theshortest distance from alkene included in IM-T21 functional group tomain chain. According to an exemplary embodiment of the presentinvention, a bonding number may be, for example, the number of singlebonds among bonds linked in the shortest distance from alkene includedin IM-T21 functional group to main chain.

According to an exemplary embodiment of the present invention, thebonding number of IM-T2 functional group may be, for example, largerabout 3 to about 7 times than that of IM-T21 functional group. If thesingle bonding number of IM-T2 exceeds about 7 times that of IM-T21, theforce for aligning liquid crystal molecules may be decreased, therebymaking the alignment of liquid crystal molecules non-uniform.

According to an exemplary embodiment of the present invention, thenumber of spacers included in IM-T2 functional group is, for example,different from that of IM-T21. The number of spacers included in IM-T2may be, for example, larger than that of IM-T21. The number of spacersincluded in IM-T2 may be, for example, larger about twice to about 5times than that of IM-T21. According to an exemplary embodiment of thepresent invention, the number of spacers included in IM-T2 may be, forexample, about 1 to about 5, and the number of spacers included inIM-T21 may be about 0 to about 4. According to an exemplary embodimentof the present invention, a spacer may be, for example, alkyl group, andthe number of spacers is the number of carbon atoms. According to anexemplary embodiment of the present invention, IM-T21 functional groupmay, for example, not comprise a spacer.

According to an exemplary embodiment of the present invention, IM-T2functional group comprises, for example, alkylated methacrylate group,and IM-T21 functional group comprises vinyl group. An alkyl groupincluded in alkylated methacrylate group may comprise, for example,about 2 to 4 carbon atoms. When an alkylated methacrylate groupincluding an alkyl group of (CH₂)₃ is bonded with siloxane, the chainlength of IM-T2 functional group is about 6 times the unit length ofcarbon-silicone bond, and the number of spacers is 3. When a vinyl groupincluded in IM-T21, of which number of spacers is 0, is bonded with asiloxane, the chain length of IM-T2 functional group is about one timethe unit length of carbon-silicone bond. Therefore, the chain length ofIM-T2 functional group is about 6 times that of IM-T21 functional group.In IM-T2 functional group of alkylated methacrylate group including analkyl group of (CH₂)₃, the single bonding number of carbon-carbon is 3,the single bonding number of carbon-oxygen is 2, and the single bondingnumber of carbon-silicone is 1. In IM-T21 functional group of vinylgroup, the single bonding number of carbon-silicone is 1. The singlebonding number of IM-T2 functional group is about 6 times that ofIM-T21. According to an exemplary embodiment of the present invention,IM-T2 functional group and IM-T21 functional group have a curing partfrom, for example, same or different materials, and the chain length orbonding number of IM-T2 is different from that of IM-T21.

According to an exemplary embodiment of the present invention, thefourth surface alignment compound can be synthesized as, for example, inthe following reaction formula IM2-M4. The fourth surface alignmentcompound can be formed by, for example, mixing tetraethyl orthosilicateinto a polar solvent (tetrahydrofuran, THF) to produce a mixture, andstirring this mixture, long alkyl, vinyl group and alkylated acrylate inwater (H₂O) comprising an acid (for example, hydrochloric acid, HCl) orbase catalyst. A long alkyl group can function as, for example, IM-T1functional group, an acrylate group can function as IM-T2 functionalgroup, a vinyl group can function as IM-T21 functional group, and ahydroxyl group can function as IM-T3 functional group. The fourthsurface alignment compound can be formed by, for example, nucleophilichydrolysis and condensation polymerization.

A process of manufacturing the alignment films 291 and 292, and theliquid crystal display panel assembly 300 using the surface alignmentreactant 10 including the pre-tilting functional groups having differentchain lengths, will be described in detail below. The surface alignmentreactant 10 including the pre-tilting functional groups (e.g., lighthardeners) having different chain lengths forms the alignment film ofthe liquid crystal display panel assembly 300 substantially by the SC-VAmode-based method. This surface alignment reactant 10 may increase incross-linking rate in the electric-field lithography process.

Based on the aforesaid method of forming the alignment films 291 and 292using the surface alignment reactant 10 formed by, for example, mixingthe inorganic-based compounds in which functional groups are bonded, amethod of forming the alignment films 291 and 292 using the surfacealignment reactant 10 including the light initiators having differentchain lengths will be described below. Duplicate descriptions will besimplified or omitted for convenience. To avoid duplicate descriptions,a method of forming the upper-plate alignment film 292 will be omitted,and only the method of forming the lower-plate alignment film 291 willbe described.

The lower display panel 100 with the pixel electrode 191 and the upperdisplay panel 200 with the common electrode 270 are manufactured in theabove/below-described methods. The surface alignment reactant 10including the pre-tilting functional groups (e.g., light initiators)having different chain lengths is formed on the pixel electrode 191 bythe aforesaid methods. The surface alignment reactant 10 having amixture of the third and fourth surface alignment compounds undergoes aprimary heating process, thereby removing its solvent.

In the primary heating process, the surface alignment reactant 10 is,for example, phase-separated into the surface inorganic layer 33 a andthe surface functional group layer 35 a. The surface inorganic layer 33a substantially includes, for example, the third surface alignmentcompound, while the surface functional group layer 35 a substantiallyincludes the fourth surface alignment compound. For example, thefunctional groups IM-T1, IM-T2, and IM-T21 of the fourth surfacealignment compound included in the surface functional group layer 35 amay be linked to the side chains of polysiloxanes, and may be arrangedsubstantially perpendicularly to the surface of the substrate or thepixel electrode 191, or arranged in contact with the air. The thirdsurface alignment compound may include, for example, a phase separationenhancer. The surface alignment reactant 10 including the phaseseparation enhancer (e.g., methyl groups) may be readily phase-separatedfor the above reasons. In the primary heating process, the siloxanesincluded in the surface inorganic layer 33 a and the surface functionalgroup layer 35 a may form the main chains including the polysiloxanes asdescribed above. After the primary heating, the surface inorganic layer33 a and the surface functional group layer 35 a may undergo alignmentfilm rework if they were formed poorly. The alignment film rework is aprocess of removing the poorly formed surface inorganic layer 33 a andsurface functional group layer 35 a, re-forming the surface alignmentreactant 10 on the pixel, and re-performing the primary heating processthereon.

The surface alignment reactant 10 including the phase-separated surfaceinorganic layer 33 a and surface functional group layer 35 a issecondarily heated in the aforesaid method. In the secondary heatingprocess, the surface functional group layer 35 a is cured in theaforesaid method, and the polysiloxanes included in the surfaceinorganic layer 33 a and the surface functional group layer 35 a mayundergo cross-linking. The surface inorganic layer 33 a forms thesurface inorganic alignment film 33 as its polysiloxanes areadditionally bonded. The primary heating process is optional. In thiscase, the reactions described with reference to the primary andsecondary heating processes may occur in the second heating process.

Thereafter, for example, the surface inorganic alignment film 33 or thesurface functional group layer 35 a is cleaned by DIW, and may befurther cleaned by IPA. After the cleaning, the surface inorganicalignment film 33 or the surface functional group layer 35 a is dried.

Thereafter, as described above, the sealant, the upper-plate commonvoltage applying point, and the liquid crystal layer 3 are formed, andthe lower and upper display panels 100 and 200 are assembled and thenannealed in the aforementioned method.

Thereafter, light is irradiated to the assembled lower and upper displaypanels 100 and 200, with an exposure voltage applied thereto. By doingso, the surface functional group layer 35 a forms the surface functionalhardening layer 35. The surface inorganic alignment film 33 and thesurface functional hardening layer 35 form the lower-plate alignmentfilm 291.

A method of forming the surface functional hardening layer 35 is similarto the method described with reference to the functional groups IM-T2 inFormulae IM2, so only differences therebetween will be described indetail. The electric-field lithography process is performed while anelectric field is formed in the liquid crystal layer 3. The functionalgroups IM-T2 and IM-T21 included in the surface functional group layer35 a are cross-linked and cured by, for example, the electric-fieldlithography process. The functional groups IM-T2 may, for example, forma network by being cross-linked to the functional groups IM-T2 orIM-T21. As for the alkenes included in the functional groups IM-T2 andthe alkenes included the functional groups IM-T21, their double bondsare unfastened by light energy, and the functional groups IM-T2 andIM-T21 are cross-linked. The alkenes included in the functional groupsIM-T2 and IM-T21 serve as reaction parts for cross-linking. As thefunctional groups IM-T2 and IM-T21 are cross-linked, the reaction partof the functional groups IM-T2 becomes a cross-linking part of thefunctional groups IM-T2, and the reaction part of the functional groupsIM-T21 becomes a cross-linking part of the functional groups IM-T21. Thefunctional groups IM-T2 and IM-T21 cured in the electric-fieldlithography process form the surface functional hardening layer 35. Thefunctional groups IM-T1 have the characteristics of the verticalalignment monomers of the vertical functional groups. The functionalgroups IM-T2, IM-T21, IM-T1 and IM-T3 may be linked to the side chainsof the polysiloxanes formed by, for example, primarily or secondarilyheating the fourth surface alignment compound. As described above, thefunctional groups IM-T2 are different from the functional groups IM-T21in chain length, making it possible to increase the cross-linking rateof the functional groups IM-T2 and IM-T21. The increase in cross-linkingrate may reduce the number of the non-hardened (non-cured) functionalgroups IM-T2 or IM-T21. In the process of manufacturing the liquidcrystal display device, the non-cured functional groups IM-T2 or IM-T21may generate impurities, or may cause the pre-tilt angle to be irregularby being cured later on. The increase in cross-linking rate may increasethe reliability or the quality of the liquid crystal display device, andmay make the fluorescent lithography process unnecessary. By thecross-linking, the cured functional groups IM-T2 and IM-T21 arrangetheir adjacent liquid crystal molecules 31 to be tilted in thesubstantially same direction. The liquid crystal molecules 31 adjacentto the cured functional groups IM-T2 and IM-T21 may be arranged, forexample, at a substantially constant pre-tilt angle when no electricfield is applied in the liquid crystal layer 3. The surface inorganicalignment film 34 and the surface functional hardening layer 36 includedin the upper-plate alignment film 292 may be formed in theabove/below-described methods of forming the lower-plate alignment film291. The functional groups IM-T2 may be, for example, different from thefunctional groups IM-T21 in terms of the bonding number or the number ofspacers. The polysiloxanes formed by primarily or secondarily heatingthe fourth surface alignment compound are formed on the polysiloxanesformed by the third surface alignment compound.

The liquid crystal display panel assembly 300 manufactured by thesurface alignment reactant 10 including the light initiators havingdifferent chain lengths may have the characteristics of the SC-VA mode.Because the surface alignment reactant 10 includes the light initiatorshaving different chain lengths, the cross-linking rate of the lightinitiators may increase, thereby increasing the quality of the liquidcrystal display device.

In accordance with an exemplary embodiment of the present invention, thealignment films 291 and 292 formed by the surface alignment reactant 10including the light initiators having different chain lengths wasmanufactured, and the liquid crystal display device having thesealignment films was manufactured. The surface alignment reactant 10forming these alignment films was, for example, a mixture of the thirdand fourth surface alignment compounds having the following materials,mixed at the weight ratio of about 7 to about 3. The third surfacealignment compound included, for example, methyl groups of about 10 mol%, and hydroxy groups of about 90 mol %. The fourth surface alignmentcompounds included, for example, alkyl groups of about 10 mol % havingabout 17 carbons, methacrylate groups of about 40 mol % having (CH₂)₃,vinyl groups of about 10 mol %, and hydroxy groups of about 40 mol %.Mol % of each component is its mol % in the third and fourth surfacealignment compounds with the solvent excluded. The chain length of thefunctional groups IM-T2 is, for example, about 6 times the chain lengthof the functional groups IM-T21. The bonding number of the functionalgroups IM-T2 is, for example, about 6 times the bonding number of thefunctional groups IM-T21.

The liquid crystal display panel assembly 300 was manufactured accordingto the method of manufacturing the alignment films 291 and 292 using thesurface alignment reactant 10 including the light hardeners havingdifferent chain lengths. In the process of manufacturing the liquidcrystal display panel assembly 300, the surface inorganic alignment film33 or the surface functional group layer 35 a was cleaned by DIW andIPA. The pixel structure of the liquid crystal display device wassubstantially similar to that of FIG. 3. The cell spacing in the liquidcrystal layer 3 was, for example, about 3.0 μm. For example, the widthof the micro branches 197 of the pixel electrode 191 were about 5 μm,and the width of the micro slits 199 was about 3 μm. The exposurevoltage V2 supplied by the multi-step voltage supply was, for example,about 15V. The UV intensity of the electric-field lithography processwas, for example, about 6.5 J/cm². The manufactured liquid crystaldisplay device was operated by charge sharing-based 1G1D drivingdescribed with reference to FIG. 11. The stacked structure of the liquidcrystal display panel assembly 300 was as shown in FIG. 21A or 21B. Theovercoat 225 formed on the upper display panel 200 included, forexample, the acrylic materials. In the manufactured liquid crystaldisplay device, the cross-linking rate increased by about 80% or more,and the black afterimage showed a good level of about 2.5 in a 168-houroperation.

In accordance with an exemplary embodiment of the present invention, anew surface alignment reactant 10 will be described. In addition, analignment film formed using the surface alignment reactant 10 and amethod for forming the alignment film, and a liquid crystal displaydevice manufactured using the alignment film and a method formanufacturing the liquid crystal display device will be described indetail. In accordance with an exemplary embodiment of the presentinvention, the surface alignment reactant 10 forming the alignment filmincludes, for example, a monomer that is linked to a side chain of aninorganic material by a vertical functional group including rigidmolecules. The vertical functional group including rigid molecules mayincrease the vertical alignment properties of liquid crystal molecules.An increase in vertical alignment force of liquid crystal molecules mayreduce light leakage of the liquid crystal display device during itsinitial use or even after its operation for a long time, therebycontributing to the increase in display quality of the liquid crystaldisplay device.

A surface alignment reactant 10 having, for example, a verticalfunctional group including a rigid molecule is a mixture of the fifthsurface alignment compound and the sixth surface alignment compound. Asdescribed above, surface alignment reactants 10 of which compounds aremixed with each other can be readily phase-separated in a process offorming an alignment film. The fifth surface alignment compound issubstantially similar with the first or third surface alignment compounddescribed above. The sixth surface alignment compound may comprise apre-tilt functional group or a vertical functional group. According toan exemplary embodiment of the present invention, the sixth surfacealignment compound is, for example, linked with a side chain ofinorganic-based materials, and includes a vertical functional groupincluding a rigid molecule. According to an exemplary embodiment of thepresent invention, the fifth surface alignment compound and the sixthsurface alignment compound can be mixed, for example, in a weight ratioof about 6˜about 8 to about 2˜about 4. A solvent is not included in theweight ratio of the fifth surface alignment compound and the sixthsurface alignment compound. The weight of solid contents included in asurface alignment reactant 10, e.g., the combined weight of the fifthsurface alignment compound and the sixth surface alignment compound, maybe, for example, about 2 wt % to about 4 wt %, and the weight of asolvent may be, for example, about 96 wt % to about 98 wt %. A solventmay be, for example, any one selected from solvents described above. Thefifth surface alignment compound and the sixth surface alignmentcompound can be mixed, for example, in a weight ratio of about 7 toabout 3. The combined weight of the fifth surface alignment compound andthe sixth surface alignment compound included in a surface alignmentreactant 10 may be, for example, about 3 wt %, and that of a solvent maybe, for example, about 97 wt %.

According to an exemplary embodiment of the present invention, the fifthsurface alignment compound comprises, for example, the above-describedformula IM1 or the following formula IM5. A siloxane group monomerforming a main chain is linked with IM-R6 and IM-A6 functional groupsforming side chains to form formula IM5. The fifth surface alignmentcompound may comprise, for example, IM-R6 of about 80 mol % to about 97mol %, and IM-A6 functional group of about 3 mol % to about 20 mol %. Amol % of each functional group is a mol % of the fifth surface alignmentcompound except for siloxane and a solvent. The functional groupincluded in the fifth surface alignment compound may substantially have,for example, the hydrophobic features. According to an exemplaryembodiment of the present invention, the fifth surface alignmentcompound may comprise, for example, IM-A6 functional group of about 5mol % and IM-R6 functional group of about 95 mol %. Formula IM1 has beendescribed above.

IM-A6 functional group may be an aggregation inhibitor. An aggregationinhibitor can prevent compounds from separately aggregating. Forexample, IM-A6 functional group can reduce excessive segregation of thefifth surface alignment compound and the sixth surface alignmentcompound, such that the sixth surface alignment compounds get togetherto be separated from the fifth surface alignment compounds. IM-A6functional group may comprise, for example, an alkylated amine havingabout 1 to about 5 carbon atoms. IM-A6 functional group may havehydrophobic features. IM-A6 functional group may comprise, for example,an amine group or a thiol group. IM-R6 functional group has beendescribed above with reference to formula IM1.

According to an exemplary embodiment of the present invention, acompound of formula IM5 can be synthesized by, for example, the processdescribed below. First, monomers of IM-R6 portion and monomers of IM-A6portion are manufactured by the process described below. Then, monomersof IM-R6 portion and monomers of IM-A6 portion are mixed with a solventin the composition ratio described above, and heated at, for example,about 60° C. to be formed as a compound of formula IM5 by polymerizingmonomers. A solvent used in this process may be, for example, any oneselected from the above-described solvents capable of mixing the firstsurface alignment compound and the second surface alignment compound. Amonomer of IM-R6 portion may be, for example, orthosilic acid, Si(OH)4.Orthosilic acid, Si(OH)4 can be prepared by, for example, mixingtetraethyl orthosilicate in a polar solvent, for example,tetrahydrofuran (THF) to produce a mixture, and stirring this mixturewith water (H₂O) comprising an acid (for example, hydrochloric acid,HCl) or base catalyst. A monomer of IM-R6 portion may be one comprisinga siloxane of which one of bonds is substituted with alkylated amine. Asiloxane of which one of bonds is substituted with alkylated amine canbe prepared by, for example, mixing tetraethyl orthosilicate in a polarsolvent, for example, tetrahydrofuran (THF) to produce a mixture, andstirring this mixture and an alkylated amine with water (H₂O) comprisingan acid (for example, hydrochloric acid, HCl) or base catalyst.

The sixth surface alignment compound will be described in detail below.The sixth surface alignment compound has, for example, a verticalfunctional group including a rigid molecule. According to an exemplaryembodiment of the present invention, the sixth surface alignmentcompound comprises, for example, the following formula IM6. A siloxanegroup monomer forming a main chain is linked with IM-T11, IM-T2, IM-T21,IM-R6 and IM-T4 functional groups forming side chains to form formulaIM6. The sixth surface alignment compound may comprise, for example,IM-T11 functional group of about 5 mol % to about 25 mol %, IM-T2functional group of about 35 mol % to about 55 mol %, IM-T21 functionalgroup of about 5 mol % to about 15 mol %, IM-R6 functional group ofabout 25 mol % to about 40 mol %, and IM-T4 functional group of about 1mol % to about 5 mol %. A mol % of each functional group is a mol % ofthe sixth surface alignment compound except for siloxane and a solvent.IM-T11, IM-T2, and IM-T21 functional groups included in the sixthsurface alignment compound may, for example, substantially have thehydrophobic features. According to an exemplary embodiment of thepresent invention, the sixth surface alignment compound may comprise,for example, IM-T11 functional group of about 8 mol %, IM-T2 functionalgroup of about 45 mol %, IM-T21 functional group of about 10 mol %,IM-R6 functional group of about 34 mol %, and IM-T4 functional group ofabout 3 mol %.

IM-T11 functional group comprises, for example, a rigid molecule, and isa monomer of a vertical alignment component which reacts with liquidcrystal molecules to align liquid crystal molecules perpendicularly to alower layer. IM-T11 functional group comprising a rigid molecule allowsliquid crystal molecules to be more stably aligned perpendicularly. AsIM-T11 functional groups can increase the vertical aligning force ofliquid crystal molecules, black light leakage of a liquid crystaldisplay device including them can be reduced. IM-T11 functional group isa linkage of a rigid molecule and alkyl group. A rigid molecule may be,for example, a cyclic compound. According to an exemplary embodiment ofthe present invention, a rigid molecule may include, for example,benzene, cyclohexane, biphenyl, or combinations thereof. According to anexemplary embodiment of the present invention, the number of carbonatoms of alkyl group may be, for example, about 16 or less. IM-T11functional group may include the following formula XIX-A5, XIX-A6,XIX-A7, XIX-A8 or XIX-A9.

where x may be about 1 to about 20, y may be about 1 to about 10, R maybe CH₃, HCOO—, CH₂═CH—, CH₂S—, CH₃O—, CH₃S—, or CH₂CH—COO—, and B and Cmay be H, F, Cl, Br, I, CN, SCN, SF₅H, or NO_(2.)

IM-T11 functional group may include, for example, a cholesteric groupmonomer represented by the above mentioned formula XIX-A2, an alkylatedalicyclic group monomer represented by formula XIX-A3, and an alkylatedaromatic group monomer represented by formula XIX-A4. A rigid moleculemay have a linkage between silicone (Si) and an alkyl group. Accordingto the present invention, IM-T11 functional group may include, forexample, an alkyl benzene group having about 6 to about 12 carbon atoms.

IM-T4 functional group may be a catalyst for sol-gel reaction, forexample, dehydration. IM-T4 functional group can increase thecross-linking density of polysiloxane. IM-T4 functional group mayinclude, for example, the material described above with reference toIM-A6 functional group. As alkylated amine substantially has hydrophobicfeatures, an alignment film formed by a surface alignment reactant 10comprising alkylated amine group may not collect impurities. The imagequality of a liquid crystal display device may be increased by this.IM-T4 functional group can serve as IM-A6 functional group describedabove with reference to IM5. For reducing the excessive separation intoseparate surface alignment compounds caused by separate agglomeration ofsurface alignment compounds, only one of IM-T4 functional group andIM-A6 functional group can be included in the fifth or sixth surfacealignment compound. According to an exemplary embodiment of the presentinvention, IM-T4 functional group is not included in the sixth surfacealignment compound, while IM-A6 functional group is included in thefifth surface alignment compound. IM-T2, IM-T21 and IM-R6 functionalgroups have been described above with reference to formulas IM1, IM2 andIM4.

According an exemplary embodiment of the present invention, a compoundof formula IM6 can be synthesized by, for example, the process describedbelow. First, monomers of IM-T11 portion, monomers of IM-T2 portion,monomers of IM-T21 portion, monomers of IM-R6 portion and monomers ofIM-T4 portion are manufactured by the process described below. Then, acompound of formula IM6 can be synthesized by, for example, mixingmonomers of IM-T11 portion, monomers of IM-T2 portion, monomers ofIM-T21 portion, monomers of IM-R6 portion and monomers of IM-T4 portionin the composition ratio described above, and heating the resultingmixture at about 50 to 70° C. to polymerize monomers. A solvent used inthis process may be, for example, any one selected from theabove-described solvents capable of mixing the first surface alignmentcompound and the second surface alignment compound.

According to an exemplary embodiment of the present invention, monomersof IM-T11 may be, for example, siloxane of which any bond is substitutedwith alkyl benzene. A siloxane of which any bond is substituted withalkyl benzene can be prepared by, for example, mixing tetraethylorthosilicate in a polar solvent, for example, tetrahydrofuran (THF) toproduce a mixture, and stirring this mixture and alkyl benzene withwater (H₂O) comprising an acid (for example, hydrochloric acid, HCl) orbase catalyst. The alkyl group has about 6 to about 12 carbon atoms.According to an exemplary embodiment of the present invention, alkylbenzene can be replaced with, for example, any of above-describedmolecules included in IM-T11 functional group.

According to an exemplary embodiment of the present invention, monomersof IM-T2 may be, for example, siloxane of which any bond is substitutedwith alkylated methacrylate. A siloxane of which any bond is substitutedwith alkylated methacrylate can be prepared by, for example, mixingtetraethyl orthosilicate (TEOS) in a polar solvent, for example,tetrahydrofuran (THF) to produce a mixture, and stirring this mixtureand alkylated methacrylate with water (H₂O) comprising an acid (forexample, hydrochloric acid, HCl) or base catalyst. The alkyl group has,for example, about 1 to about 7 carbon atoms. According to an exemplaryembodiment of the present invention, alkylated methacrylate can bereplaced with, for example, any one of above-described moleculesincluded in IM-T2 functional group.

According to an exemplary embodiment of the present invention, monomersof IM-T21 may be, for example, siloxane of which any bond is substitutedwith vinyl group. A siloxane of which any bond is substituted with vinylgroup can be prepared by, for example, mixing tetraethyl orthosilicate(TEOS) in a polar solvent, for example, tetrahydrofuran (THF) to producea mixture, and stirring this mixture and vinyl group with water (H₂O)comprising an acid (for example, hydrochloric acid, HCl) or basecatalyst. The number of spacers linked with vinyl group, for example,the number of carbon atoms of alkyl group may be 0 to about 4. Accordingto an exemplary embodiment of the present invention, vinyl group can bereplaced with, for example, any one of above-described moleculesincluded in IM-T21 functional group.

According to an exemplary embodiment of the present invention, monomersof IM-R6 may be, for example, siloxane of which any bond is substitutedwith hydroxyl group. A siloxane of which any bond is substituted withhydroxyl group can be prepared by, for example, mixing tetraethylorthosilicate in a polar solvent, for example, tetrahydrofuran (THF) toproduce a mixture, and stirring this mixture and hydroxyl group withwater (H₂O) comprising an acid (for example, hydrochloric acid, HCl) orbase catalyst. According to an exemplary embodiment of the presentinvention, hydroxyl group can be replaced with, for example, any one ofabove-described molecules included in IM-R6 functional group.

According to an exemplary embodiment of the present invention, monomersof IM-T4 may be, for example, siloxane of which any bond is substitutedwith alkylated amine group. A siloxane of which any bond is substitutedwith alkylated amine group can be prepared by, for example, mixingtetraethyl orthosilicate in a polar solvent, for example,tetrahydrofuran (THF) to produce a mixture, and stirring this mixtureand alkylated amine group with water (H₂O) comprising an acid (forexample, hydrochloric acid, HCl) or base catalyst. The alkyl group has,for example, about 1 to about 5 carbon atoms. According to an exemplaryembodiment of the present invention, alkylated amine group can bereplaced with, for example, any one of above-described moleculesincluded in IM-T4 functional group.

A process of manufacturing alignment films 291 and 292 and a liquidcrystal display panel assembly 300 using the surface alignment reactant10 including a rigid monomer linked to a side chain of the inorganicmaterial will be described in detail below. In accordance with anexemplary embodiment of the present invention, the surface alignmentreactant 10 including a rigid monomer linked to a side chain of theinorganic material includes a vertical functional group including rigidmolecules that are linked to a main chain of the inorganic material anda side chain of the inorganic material as described above. The surfacealignment reactant 10 including a rigid monomer linked to a side chainof the inorganic material substantially forms the alignment film and theliquid crystal display panel assembly 300 by the above-described SC-VAmode-based manufacturing method. As described above, the verticalfunctional group including rigid molecules may increase verticalalignment properties of liquid crystal molecules.

Based on the above-described method for forming the alignment films 291and 292 and the liquid crystal display panel assembly 300 using thesurface alignment reactant 10 formed by mixing inorganic-based compoundsin which functional groups are bonded, a method for forming the surfacealignment reactant 10 including a rigid monomer linked to a side chainof the inorganic material on the alignment films 291 and 292 and in theliquid crystal display panel assembly 300 will be described below.Duplicate descriptions will be simplified or omitted for convenience. Toavoid duplicate descriptions, a method of forming the upper-platealignment film 292 will be omitted, and only the method of forming thelower-plate alignment film 291 will be described.

A lower display panel 100 with a pixel electrode 191 and an upperdisplay panel 200 with a common electrode 270 are manufactured using theabove/below-described methods.

The surface alignment reactant 10 including, for example, a rigidmonomer linked to a side chain of the inorganic material is formed onthe pixel electrode 191 by the above-described methods. The surfacealignment reactant 10 including, for example, a mixture of theabove-described fifth and sixth surface alignment compounds undergoes aprimary heating process in the above-described method, thereby removinga solvent thereof. In the primary heating process, the surface alignmentreactant 10 is, for example, phase-separated into a surface inorganiclayer 33 a including the fifth surface alignment compound and a surfacefunctional group layer 35 a including a sixth surface alignmentcompound. The fifth surface alignment compound is formed, for example,near the pixel electrode 191 or the common electrode 270, and the sixthsurface alignment compound moves to the air layer as it includesfunctional groups having hydrophobic features. IM-A6 functional groupincluded in the fifth surface alignment compound may prevent the fifthand sixth surface alignment compounds from being completelyphase-separated and aggregating independently. In the primary heatingprocess, dehydration occurs slightly and some of siloxanes included inthe fifth and sixth surface alignment compounds are polymerized, formingpolysiloxane.

The phase-separated surface alignment reactant 10 undergoes secondaryheating in the above-described method. In the secondary heading process,dehydration occurs mainly and siloxanes and polysiloxanes included inthe surface inorganic layer 33 a and the surface functional group layer35 a are cured by being cross-linked to each other. As the siloxanes orpolysiloxanes are cross-linked or cured, the surface inorganic layer 33a forms a surface inorganic alignment film 33. In accordance with anexemplary embodiment of the present invention, in the primary and/orsecondary heating processes, IM-T4 functional group may acceleratedehydration and increase cross-linking of siloxanes. An increase incross-linking of siloxanes may cause a reduction in the amount ofhydroxyl groups included in the surface inorganic alignment film 33 andthe surface functional group layer 35 a. If the alignment film 291formed by the surface inorganic alignment film 33 and the surfacefunctional group layer 35 a includes a lesser amount of hydroxyl groups,the alignment film 291 may gather less impurities because of the smallamount of hydroxyl groups having polarity, thus contributing to areduction in liquid crystal display device's stains occurring due to theimpurities. In an embodiment, any one of the primary and secondaryheating processes may be omitted, and in the other heating process, theabove-described reactions may occur with reference to the primary andsecondary heating processes.

Thereafter, for example, the surface inorganic alignment film 33 or thesurface functional group layer 35 a is cleaned by DIW, and may beadditionally cleaned by IPA. Thereafter, the surface inorganic alignmentfilm 33 or the surface functional group layer 35 a is dried.

Thereafter, as described above, a sealant, an upper-plate common voltageapplying point, and a liquid crystal layer 3 are formed, and the lowerand upper display panels 100 and 200 are assembled. The assembled lowerand upper display panels 100 and 200 may be annealed in theabove-described method.

Thereafter, light is irradiated to the assembled lower and upper displaypanels 100 and 200 to which an exposure voltage has been supplied. Then,the surface functional group layer 35 a forms a surface functionalhardening layer 35. The surface inorganic alignment film 33 and thesurface functional hardening layer 35 form the lower-plate alignmentfilm 291. As a method for forming the surface functional hardening layer35 is similar to the method described with reference to Formula IM4,differences between the methods will be described in detail. Theelectric-field lithography process is performed by the above-describedmethods while an electric field is formed in the liquid crystal layer 3by the above-described methods. IM-T2 functional groups and IM-T21functional groups that are included the surface functional group layer35 a by the electric-field lithography process, for example, form anetwork by the above-described method, forming the surface functionalhardening layer 35. The functional groups having formed the network havea pre-tilt angle as described above, and align the surrounding liquidcrystal molecules 31 to be tilted in a direction substantially parallelto a direction of the pre-tilt angle. The IM-T11 functional groupshaving vertical alignment properties may prevent the liquid crystalmolecules 31 from being aligned to be excessively tilted. If the liquidcrystal molecules 31 are aligned to be excessively tilted, black lightleakage may occur, thereby deteriorating the display quality of theliquid crystal display device. As described above, the IM-T11 functionalgroups may align the liquid crystal molecules 31 to be less tiltedbecause they have vertical alignment properties and include rigidmolecules. Owing to the IM-T11 functional groups, the liquid crystalmolecules 31 may be more rigidly aligned and their tilt angle may beadjusted. The liquid crystal molecules 31 may be aligned at apredetermined pre-tilt angle by the IM-T11, IM-T2 and IM-T21 functionalgroups, with no electric field applied to the liquid crystal layer 3.The predetermined pre-tilt angle has been described above. Thelower-plate alignment film 291 formed in this way has a combinedstructure of polysiloxane and the above functional groups. In accordancewith an exemplary embodiment of the present invention, a mol %composition ratio of IM-T11 functional group bonded to polysiloxane toIM-T2 functional group may be, for example, about 1:about 1.5 to about11. A mol % composition ratio of IM-T11 functional group bonded topolysiloxane, IM-T2 functional group, to IM-T21 functional group may be,for example, about 1:about 1.5 to about 11:about 1 to about 3. A mol %composition ratio of IM-T11 functional group bonded to polysiloxane,IM-T2 functional group, to IM-T4 functional group may be, for example,about 1:about 1.5 to about 11:about 0.5 to about 4. In accordance withan exemplary embodiment of the present invention, a relative ratio ofany of IM-T11, IM-T2, IM-T21 and IM-T4 functional groups linked topolysiloxane may be a comparison with mol % of each one included in thefifth and sixth surface alignment compounds. The surface inorganicalignment film 34 and the surface functional hardening layer 36 includedin the upper-plate alignment film 292 may be formed in theabove/below-described methods of forming the upper-plate alignment film292.

The liquid crystal display panel assembly 300 manufactured by thesurface alignment reactant 10 including a rigid monomer linked to a sidechain of the inorganic material may have the characteristics of theSC-VA mode. The vertical functional group may reduce the light leakagedefects of the liquid crystal display device because it includes rigidmolecules. Amine group with no polarity may increase the picture qualityof the liquid crystal display device because it can increase reliabilityof the alignment film by increasing cross-linking density ofpolysiloxanes and does not collect impurities.

In accordance with an exemplary embodiment of the present invention, thealignment films 291 and 292 were manufactured with the surface alignmentreactant 10 including a rigid monomer linked to a side chain of theinorganic material, and the liquid crystal display device having thesame was manufactured. The surface alignment reactant 10 including arigid monomer linked to a side chain of the inorganic material includedsolvent and solid contents which were mixed at, for example, a weightratio of about 97 to about 3. The solid content included the fifth andsixth surface alignment compounds which were mixed at a weight ratio of,for example, about 7 to about 3. The solvent included, for example,hexylene glycol (HG) of about 55 wt %, butyl cellosolve (BCS) of about20 wt %, and propylene glycol monobutyl ether (PB) of about 25 wt %. Thefifth surface alignment compound included, for example, Formula IM5. Thefifth surface alignment compound included, for example, IM-A6 functionalgroup of about 5 mol %, and IM-R6 functional group of about 95 mol %.The IM-A6 functional group was, for example, hydroxyl group, and theIM-A6 functional group was, for example, alkylated amine having 3 carbonatoms. The sixth surface alignment compound included Formula IM6. Thesixth surface alignment compound included, for example, IM-T11functional group of about 10 mol %, IM-T2 functional group of about 45mol %, IM-T21 functional group of about 10 mol %, IM-R6 functional groupof about 32 mol %, and IM-T4 functional group of about 3 mol %. TheIM-T11 functional group was, for example, alkyl benzene having about 10carbon atoms. The IM-T2 functional group was, for example, alkylatedmethacrylate group having about 5 carbon atoms. The IM-T21 functionalgroup was, for example, alkylated vinyl group having about 3 carbonatoms. The IM-R6 functional group was, for example, hydroxyl group, andthe IM-T4 functional group was alkylated amine having three carbonatoms. The liquid crystal display panel assembly 300 was manufacturedusing the surface alignment reactant 10 including a rigid monomer linkedto a side chain of the inorganic material in accordance with theabove-described method. The surface inorganic alignment film 33 and thesurface functional group layer 35 a were, for example, cleaned by DIWand IPA in the above-described process of manufacturing the liquidcrystal display panel assembly 300. A structure of the pixel PX of theliquid crystal display device is substantially similar to the structurein FIG. 3. The liquid crystal display panel assembly 300 has the stackedstructure shown in FIG. 21A or 21B. The overcoat 225 formed on the upperdisplay panel 200 included an acrylic material. The cell spacing in theliquid crystal layer 3 was, for example, about 3.0 μm. The width of themicro branches 197 of the pixel electrode 191 were, for example, about 5μm, and the width of the micro slits 199 was, for example, about 3 μm.The exposure voltage V2 supplied by the multi-step voltage supply was,for example, about 22V. The UV intensity of the electric-fieldlithography process was, for example, about 6.5 J/cm². The manufacturedliquid crystal display device was operated by charge sharing-based 1G1Ddriving described with reference to FIG. 11. The black light leakage wasincreased in the manufactured liquid crystal display device.

In accordance with an exemplary embodiment of the present invention, anew surface alignment reactant 10, and an alignment film or a liquidcrystal display device formed using the same will be described. Thesurface alignment reactant 10 forming the alignment film is a mixtureof, for example, 3 different types of compounds. For example, the 3types of compounds, one compound comprises a first vertical functionalgroup including flexible molecules, another compound comprises a secondvertical functional group including rigid molecules, and the othercompound comprises no vertical functional group. The amounts of thefirst and second vertical functional groups may be readily adjusted bymanufacturing the compound including, for example, the first verticalfunctional group and the compound including the second verticalfunctional group independently. As the pre-tilt angle and response speedof the liquid crystal molecules depend on the amounts of the first andsecond vertical functional groups, the liquid crystal display devicecomprising these vertical functional groups may have the response speedand black light leakage characteristics which are adjusted in balance.

The surface alignment reactant 10 including, for example, a mixture of 3different types of compounds is a mixture of seventh, eighth, and ninthsurface alignment compounds. The eighth surface alignment compoundcomprises, for example, the first vertical functional group includingflexible molecules, and the ninth surface alignment compound comprisesthe second vertical functional group including rigid molecules. A weightof solid contents included in the surface alignment reactant 10, e.g., asum of the weights of the seventh, eighth and ninth surface alignmentcompounds, may be, for example, about 2 wt % to about 4 wt %, and asolvent thereof may be, for example, about 96 wt % to about 98 wt %. Inaccordance with an exemplary embodiment of the present invention, theseventh, eighth and ninth surface alignment compounds may be mixed, forexample, at a weight ratio of about 6 to about 8.5:about 0.5 to about2:about 1 to about 2. The weight of the ninth surface alignment compoundmay be, for example, about 0.5 times to about 4 times the weight of theeighth surface alignment compound.

The seventh, eighth and ninth surface alignment compounds will bedescribed below. In accordance with an exemplary embodiment of thepresent invention, the seventh surface alignment compound may include,for example, Formula IM1 or IM5, and has the characteristics describedin conjunction with the formula. Formula IM1 or IM5 may be synthesizedin the above-described method.

According to an exemplary embodiment of the present invention, theeighth surface alignment compound comprises, for example, the firstvertical functional group including a flexible molecule. According to anexemplary embodiment of the present invention, the eighth surfacealignment compound includes, for example, the following formula IM7. Asiloxane group monomer forming a main chain is linked with IM-T12,IM-T2, IM-T21, IM-R6 and IM-T4 functional groups forming side chains toform formula IM7. The eighth surface alignment compound may comprise,for example, IM-T12 functional group of about 5 mol % to about 30 mol %,IM-T2 functional group of about 40 mol % to about 60 mol %, IM-T21functional group of about 5 mol % to about 15 mol %, IM-R6 functionalgroup of about 20 mol % to about 40 mol %, and IM-T4 functional group ofabout 1 mol % to about 5 mol %. A mol % of each functional group is amol % of the eighth surface alignment compound except for siloxane and asolvent. IM-T12, IM-T2, and IM-T21 functional groups included in theeighth surface alignment compound may, for example, substantially havethe hydrophobic features. According to an exemplary embodiment of thepresent invention, the eighth surface alignment compound may comprise,for example, IM-T12 functional group of about 10 mol %, IM-T2 functionalgroup of about 50 mol %, IM-T21 functional group of about 10 mol %,IM-R6 functional group of about 27 mol % and IM-T4 functional group ofabout 3 mol %.

IM-T12 functional group is, for example, the first vertical functionalgroup comprised of flexible molecules. IM-T12 functional group or thefirst vertical functional group is a monomer of a vertical alignmentcomponent which interacts with liquid crystal molecules to align liquidcrystal molecules perpendicular to a lower layer. As liquid crystalmolecules, which interact with IM-T12 functional group or the firstvertical functional group comprised of flexible molecules, can morequickly move, the liquid crystal display device comprising them can havefast response time. A flexible molecule included in IM-T12 functionalgroup may comprise, for example, the above-described formula XIX-A1 orlong alkyl group. IM-T12 functional group may comprise, for example,about 5 to about 20 carbon atoms. IM-T2, IM-T21, IM-R6 and IM-T4functional groups have been described above with reference to formulasIM1, IM2, IM4 and IM6, and may have the effects described above.

According to an exemplary embodiment of the present invention, acompound of formula IM7 can be synthesized by, for example, the processdescribed below. First, monomer of IM-T12 portion, monomer of IM-T2portion, monomer of IM-T21 portion, monomer of IM-R6 portion, andmonomer of IM-T4 portion are prepared by, for example, the processdescribed below. Then, monomer of IM-T12 portion, monomer of IM-T2portion, monomer of IM-T21 portion, monomer of IM-R6 portion, andmonomer of IM-T4 portion are mixed with a solvent in the compositionratio described above, and heated at about 50 to 70° C. to besynthesized with, for example, a compound of formula IM7 by polymerizingmonomers. A solvent used in this process may be, for example, any oneselected from the above-described solvents capable of mixing the firstsurface alignment compound and the second surface alignment compound.According to an exemplary embodiment of the present invention, monomersof IM-T12 may be, for example, siloxane of which any bond is substitutedwith alkyl group. A siloxane of which any bond is substituted with alkylgroup can be prepared by, for example, mixing tetraethyl orthosilicate(TEOS) in a polar solvent, for example, tetrahydrofuran (THF) to producea mixture, and stirring this mixture and alkyl group with water (H₂O)comprising an acid (for example, hydrochloric acid, HCl) or basecatalyst. The alkyl group has about 5 to about 20 carbon atoms.According to an exemplary embodiment of the present invention, alkylgroup can be replaced with, for example, any one of above-describedflexible molecules included in IM-T12 functional group. Monomer of IM-T2portion, monomer of IM-T21 portion, monomer of IM-R6 portion, andmonomer of IM-T4 portion can be prepared by, for example, the processdescribed above with reference to formula IM6.

According to an exemplary embodiment of the present invention, the ninthsurface alignment compound comprises, for example, the second verticalfunctional group including a rigid molecule. The ninth surface alignmentcompound may comprise, for example, formula IM6, and has the featuredescribed above. Formula IM6 can be synthesized by, for example, theprocess described above. The seventh, eighth and ninth surface alignmentcompounds form alignment films 291 and 292 by, for example, the processdescribed below. An alignment film 291 formed by the seventh, eighth andninth surface alignment compounds has the structure in which theabove-mentioned functional groups are linked with polysiloxane. Therelative ratio of any of IM-T11, IM-T12, IM-T2, IM-T21 and IM-T4functional groups linked with polysiloxane may be a comparison with mol% of each one included in the seventh, eighth and ninth surfacealignment compounds. According to an exemplary embodiment of the presentinvention, the mol % composition ratio of IM-T11 functional group linkedwith polysiloxane to IM-T2 functional group may be, for example, about1:about 1.5 to about 11:about 11. According to an exemplary embodimentof the present invention, the mol % composition ratio of IM-T11functional group linked with polysiloxane to IM-T2 functional group toIM-T21 functional group may be, for example, about 1:about 1.5 to about11:about 0.5 to about 3. According to an exemplary embodiment of thepresent invention, the mol % composition ratio of IM-T11 functionalgroup linked with polysiloxane to IM-T2 functional group to IM-T4functional group may be, for example, about 1:about 1.5 to about11:about 0.5 to about 4. According to an exemplary embodiment of thepresent invention, the mol % composition ratio of IM-T11 functionalgroup linked with polysiloxane to IM-T12 functional group to IM-T2functional group may be, for example, about 1:about 0.3 to about 3:about1.5 to about 11.

A process of manufacturing alignment films 291 and 292 and a liquidcrystal display panel assembly 300 using the surface alignment reactant10 comprising a mixture of, for example, 3 different types of compoundswill be described in detail below. In accordance with an exemplaryembodiment of the present invention, the method of manufacturing thealignment films 291 and 292 and the liquid crystal display panelassembly 300 using the surface alignment reactant 10 comprising amixture of 3 different types of compounds is, for example, substantiallythe same as the above-described method of manufacturing the alignmentfilms 291 and 292 and the liquid crystal display panel assembly 300using the surface alignment reactant 10 comprising a rigid monomerlinked to a side chain of the inorganic material.

Based on the above-described method of manufacturing the alignment films291 and 292 and the liquid crystal display panel assembly 300 using thesurface alignment reactant 10 comprising a rigid monomer linked to aside chain of the inorganic material, the alignment films 291 and 292and the liquid crystal display panel assembly 300 were manufacturedusing the below-described surface alignment reactant 10. A manufacturingprocess thereof will be described in detail below. To avoid duplicatedescriptions, a method of forming the upper-plate alignment film 292will be omitted, and only the method of forming the lower-platealignment film 291 will be described.

First, a lower display panel 100 with a pixel electrode 191 and an upperdisplay panel 200 with a common electrode 270 were manufactured using,for example, the above/below-described methods. A pixel PX with a pixelelectrode and a common electrode had the structure of FIG. 3 and thestacked structure of FIG. 21A or 21B. For example, micro branches 197 ofthe pixel electrode 191 were about 5 μm in width and micro slits thereofwere about in 3 μm width. An overcoat 225 formed on the upper displaypanel 200 comprised, for example, an acrylic group material. Thereafter,the below-described surface alignment reactant 10 comprising a mixtureof 3 different types of compounds was formed on the pixel electrode 191by, for example, an inkjet process.

According to an exemplary embodiment of the present invention, a surfacealignment reactant 10 including a mixture of three kinds of compoundswas a combination of, for example, about 3 wt % of solid contents andabout 97 wt % of solvent. The solid contents included, for example,about 80 wt % of the seventh surface alignment compound, about 5 wt % ofthe eighth surface alignment compound, and about 15 wt % of the ninthsurface alignment compound. The seventh surface alignment compound hadthe feature of, for example, formula IM5, and comprised, for example,about 5 mol % of IM-A6 functional group and about 95 mol % of IM-A6functional group forming side chains of siloxane group monomer. IM-R6functional group was, for example, a hydroxyl group, and IM-A6functional group was, for example, an alkylated amine having about 3carbon atoms. The eighth surface alignment compound included, forexample, formula IM7 described above. For example, the eighth surfacealignment compound comprised about 14 mol % of IM-T12 functional group,about 46 mol % of IM-T2 functional group, about 10 mol % of IM-T21functional group, about 27 mol % of IM-R6 functional group and about 3mol % of IM-T4 functional group. IM-T12 functional group comprised, forexample, a long alkyl which is a flexible molecule as the first verticalfunctional group. A long alkyl comprised, for example, about 16 carbonatoms. IM-T2 functional group comprised, for example, an alkylatedmethacrylate group. An alkyl group included, for example, in alkylatedmethacrylate group comprised about 3 carbon atoms. IM-T21 functionalgroup comprised, for example, a vinyl group. The number of spacerslinked with a vinyl group was, for example, 0 (zero). IM-R6 functionalgroup was, for example, a hydroxyl group. IM-T4 functional group was,for example, an alkylated amine. An alkyl group included in alkylatedamine comprised, for example, about 3 carbon atoms. The ninth surfacealignment compound included formula IM6 described above. For example,the ninth surface alignment compound comprised about 14 mol % of IM-T11functional group, about 46 mol % of IM-T2 functional group, about 10 mol% of IM-T21 functional group, about 27 mol % of IM-R6 functional groupand about 3 mol % of IM-T4 functional group. IM-T11 functional groupcomprised, for example, an alkyl benzene including benzene which is arigid molecule as the second vertical functional group. An alkylincluded in alkyl benzene comprised about 10 carbon atoms. IM-T2functional group, IM-T21 functional group, IM-R6 functional group, andIM-T4 functional group were the same as the above-mentioned functionalgroups included in the eighth surface alignment compound. A solventcomprised about 55 wt % of hexylene glycol (HG), about 20 wt % of butylcellosolve (BCS), and about 25 wt % of propylene glycol monobutyl ether(PB).

The primary heating process was carried out on the surface alignmentreactant 10 formed on a pixel electrode 191. The primary heating processwas carried out, for example, at 95° C. for 120 seconds. A solvent wasremoved in the primary heating process, and the surface alignmentreactant 10 was phase-separated into a surface inorganic material layer33 a and a surface functional group layer 35 a. The surface inorganicmaterial layer 33 a formed in close proximity to a pixel electrode 191mainly comprises the seventh surface alignment compound, while thesurface functional group layer 35 a formed in close proximity to an airlayer mainly comprises the eighth surface alignment compound and theninth surface alignment compound. As IM-T11, IM-T12, IM-T2, and IM-21functional groups have a hydrophobic feature, the eighth or ninthsurface alignment compounds are formed in a direction of the air layer.The eighth surface alignment compound and the ninth surface alignmentcompound included in the surface functional group layer 35 a may be, forexample, in a randomly mixed state. As IM-T11 functional group includedin the ninth surface alignment compound is more hydrophobic than IM-T12functional group included in the eighth surface alignment compound, theninth surface alignment compound can be placed in more close proximityto the air layer, compared to the eighth surface alignment compound. Inaddition, a surface alignment reactant 10 undergoes dehydration in theprimary heating process.

After being primarily heated, the surface alignment reactant 10 wassecondarily heated. The secondary heating process was carried out, forexample, at about 220° C. for about 1000 seconds. Dehydration wascompleted in the secondary heating process, and siloxanes andpolysiloxanes included in a surface inorganic layer 33 a and a surfacefunctional group layer 35 a were cross-linked. In this way, a surfaceinorganic layer 33 a formed a surface inorganic alignment film 33. Eachfunctional group serves as described above.

Thereafter, for example, the surface inorganic alignment film 33 or thesurface functional group layer 35 a was cleaned by impurities, cleanedby IPA, and dried in sequence.

Thereafter, a sealant, an upper-plate common voltage applying point, anda liquid crystal layer 3 were formed, and the lower and upper displaypanels 100 and 200 were assembled in a vacuum. The sealant was cured by,for example, UV. The assembled display panels 100 and 200 were annealedat, for example, about 110° C. for about 2 hours. The sealant underwentheat curing during the annealing process.

Thereafter, an exposure voltage was applied and light was irradiated.The exposure voltage was applied by, for example, the multi-step voltagesupply, and V2 of the exposure voltage was about 15 volts (V), and UVintensity of the electric-field lithography process was about 6.5 J/cm².The fluorescent lithography process was omitted. By doing so, thesurface functional group layer 35 a formed the surface functionalhardening layer 35. In other words, IM-T2 and IM-T21 functional groupsincluded in the eighth and ninth surface alignment compounds had apre-tilt angle by forming a network. A lower-plate alignment film 291including the surface inorganic alignment film 33 and the surfacefunctional hardening layer 35 was formed by, for example, theabove-described process. In the lower-plate alignment film 291 formed inthis way, vertical functional groups having rigid molecules may bedistributed near the air layer or the liquid crystal layer, comparedwith the vertical functional groups having flexible molecules. A surfaceinorganic alignment film 34 and a surface functional hardening layer 36included in an upper-plate alignment film 292 were formed by, forexample, the above-described method of forming the lower-plate alignmentfilm 291. The cell spacing in the liquid crystal display device was, forexample, about 3.0 μm. The liquid crystal display device was operated bycharge sharing-based 1G1D driving described with reference to FIG. 11.

The lower/upper-plate alignment films 291 and 292 formed in this wayimproved the black light leakage defects by adjusting the pre-tilt angleof liquid crystal molecules, and could increase mobility of the liquidcrystal molecules. The alignment films 291 and 292 comprising flexiblevertical alignment functional groups and rigid vertical alignmentfunctional groups may adjust the response speed and pre-tilt angle ofthe liquid crystal molecules in balance, improving the display qualityof the liquid crystal display device.

In accordance with an exemplary embodiment of the present invention, anew surface alignment reactant 10 and an alignment film or a liquidcrystal display device formed using the same will be described. Thesurface alignment reactant 10 forming an alignment film comprises acompound including, for example, 2 different types of monomers thatalign liquid crystal molecules vertically. Any one of the 2 differenttypes of monomers included in one compound is, for example, a firstvertical functional group including flexible molecules, and the other isa second vertical functional group including rigid molecules. As thealignment film including the first vertical functional group comprisingflexible molecules and the second vertical functional group comprisingrigid molecules may adjust the pre-tilt angle and response speed of theliquid crystal molecules by the amounts of the first and second verticalfunctional groups as described above, the liquid crystal display deviceincluding this alignment film may have the response speed and blacklight leakage characteristics which are adjusted in balance. As onecompound may comprise the first vertical functional group includingflexible molecules and the second vertical functional group includingrigid molecules, the liquid crystal molecules may be aligned at a moreuniform angle and the process of forming the alignment film may besimplified.

The surface alignment reactant 10 comprising a compound having twodifferent types of monomers that align liquid crystal moleculesvertically is a mixture of, for example, tenth and eleventh surfacealignment compounds. The eleventh surface alignment compound comprises,for example, two different types of monomers that align liquid crystalmolecules vertically. A mixing ratio of the tenth and eleventh surfacealignment compounds included in the surface alignment reactant 10, amixing ratio of solid contents and a solvent, and the solvent mixingcompounds are the same as those described with reference to the fifthand sixth surface alignment compounds.

In accordance with an exemplary embodiment of the present invention, thetenth surface alignment compound may include, for example, Formula IM1or IM5, and has the characteristics described in conjunction with theformula. Formula IM1 or IM5 may be synthesized in the above-describedmethod.

According to an exemplary embodiment of the present invention, theeleventh surface alignment compound including two different kinds ofmonomers which vertically align liquid crystal molecules comprises, forexample, the following formula IM8. A siloxane group monomer forming amain chain and IM-T12, IM-T11, IM-T2, IM-T21, IM-R6 and IM-T4 functionalgroups forming side chains are linked with each other to form formulaIM8. The eleventh surface alignment compound may comprise, for example,IM-T12 functional group of about 5 mol % to about 15 mol %, IM-T11functional group of about 5 mol % to about 15 mol %, IM-T2 functionalgroup of about 35 mol % to about 55 mol %, IM-T21 functional group ofabout 5 mol % to about 15 mol %, IM-R6 functional group of about 20 mol% to about 40 mol %, and IM-T4 functional group of about 1 mol % toabout 5 mol %. A mol % of each functional group is a mol % in theeleventh surface alignment compound except for siloxane and a solvent.IM-T12, IM-T11, IM-T2, and IM-T21 functional group included in theeleventh surface alignment compound may substantially have thehydrophobic features. According to an exemplary embodiment of thepresent invention, the eleventh surface alignment compound may comprise,for example, IM-T12 functional group of about 10 mol %, IM-T11functional group of about 10 mol %, IM-T2 functional group of about 45mol %, IM-T21 functional group of about 10 mol %, IM-R6 functional groupof about 22 mol % and IM-T4 functional group of about 3 mol %.

IM-T12 functional group comprises, for example, a flexible moleculedescribed above with reference to formula IM7. IM-T11 functional groupcomprises a rigid molecule described above with reference to formulaIM6. IM-T12 functional group and IM-T11 functional group are monomers ofa vertical alignment component which interacts with liquid crystalmolecules to align liquid crystal molecules perpendicularly to a lowerlayer. IM-T12 may be the first vertical functional group describedabove, and IM-T11 may be the second vertical functional group describedabove. An alignment film, which comprises the combined IM-T12 functionalgroup and IM-T11 functional group in a certain ratio or amount asdescribed above, can increase the display quality of a liquid crystaldisplay device. As IM-T12 functional group and IM-T11 functional groupcan be uniformly distributed within one compound, the alignment ofliquid crystal molecules can be uniform. IM-T2, IM-T21, IM-R6 and IM-T4functional groups have been described above with reference to formulaIM1, formula IM2, formula IM4 and formula IM6, and may have the effectsdescribed above.

According to an exemplary embodiment of the present invention, acompound of formula IM8 can be synthesized by, for example, the processdescribed below. First, monomer of IM-T12 portion, monomer of IM-T11portion, monomer of IM-T2 portion, monomer of IM-T21 portion, monomer ofIM-R6 portion, and monomer of IM-T4 portion are prepared by the processdescribed below. Then, monomer of IM-T12 portion, monomer of IM-T11portion, monomer of IM-T2 portion, monomer of IM-T21 portion, monomer ofIM-R6 portion, and monomer of IM-T4 portion are mixed with, for example,a solvent in the composition ratio described above, and heated at about50 to 70° C. to be synthesized with a compound of formula IM8 bypolymerizing monomers. A solvent used in this process may be, forexample, any one selected from the above-described solvents capable ofmixing the first surface alignment compound and the second surfacealignment compound. According to an exemplary embodiment of the presentinvention, monomers of IM-T12 portion may be, for example, siloxane ofwhich any bond is substituted with alkyl group. A siloxane of which anybond is substituted with alkyl group can be prepared by, for example,mixing tetraethyl orthosilicate (TEOS) in a polar solvent, for example,tetrahydrofuran (THF) to produce a mixture, and stirring this mixtureand alkyl group with water (H₂O) comprising an acid (for example,hydrochloric acid, HCl) or base catalyst. The alkyl group has, forexample, about 5 to about 20 carbon atoms. According to an exemplaryembodiment of the present invention, alkyl group can be replaced with,for example, any one of above-described flexible molecules included inIM-T12 functional group. Monomer of IM-T11 portion, monomer of IM-T2portion, monomer of IM-T21 portion, monomer of IM-R6 portion, andmonomer of IM-T4 portion can be prepared by, for example, the processdescribed above with reference to formula IM6.

A surface alignment reactant 10 comprising, for example, two differentkinds of monomers which vertically align liquid crystal molecules mayform alignment films 291 and 292 and a liquid crystal display panelassembly 300 by the above-described method for forming the alignmentfilms 291 and 292 and the liquid crystal display panel assembly 300using a surface alignment reactant 10 comprising the fifth surfacealignment compound and the sixth surface alignment compound. In theformed alignment films 291 and 292, vertical functional groups includinga flexible molecule and vertical functional groups including a rigidmolecule may be distributed without being separated from each other. Thealignment film 291 formed by the tenth and eleventh surface alignmentcompounds has a structure of which polysiloxane and the above-describedfunctional groups are linked to each other. The relative ratio of any ofIM-T11, IM-T12, IM-T2, IM-T21 and IM-T4 functional groups linked withpolysiloxane may be a comparison with mol % of each one included in theseventh, eighth and ninth surface alignment compounds.

A sealant according to an exemplary embodiment of the present inventionis cured in light having a wavelength of about 400 nm or more. By thelight having a wavelength of about 400 nm or more, the sealant is curedand the light hardeners existing in an inner region of the lower orupper display panel are not cured, reducing edge stain defects occurringaround the sealant. As the sealant cured in UV with a wavelength ofabout 300 nm to about 400 nm is cured by the light curing lighthardeners included in a material forming the alignment film or theliquid crystal, the light hardeners around the sealant are cured whenthe sealant is cured. Thus, the liquid crystal display device could haveedge stain defects. To address this difficulty, the sealant and thelight hardener are required to be cured in light having differentwavelengths.

The sealant that is cured in light with a wavelength of about 400 nm ormore according to an exemplary embodiment of the present invention issubstantially the same as that applied in the above-described processesexcept for a material of the sealant and a method of curing the sealant.Therefore, duplicate descriptions of the sealant process will be omittedfor convenience of description.

The sealant that is cured in light with a wavelength of about 400 nm ormore according to an exemplary embodiment of the present invention maybe applied onto the lower or upper display panel in accordance with theliquid crystal display panel assembly manufacturing methods describedabout or below with reference to FIGS. 6A, 6B and 6C, e.g., to the SVAmode, the SC-VA mode and the polarized UV-VA mode. The applied sealantis cured in light with a wavelength of, for example, about 400 nm ormore. The light with a wavelength of about 400 nm or more may be visibleray.

As the sealant according to an exemplary embodiment of the presentinvention is cured in light with a wavelength of about 400 nm or more,light hardeners forming the alignment film or included in the liquidcrystal layer 3 are not cured even though the light irradiated to thesealant is partially mis-irradiated to the periphery of the sealant.Therefore, the shield mask may not be required, which was required toblock the light irradiated to the sealant from being mis-irradiated tothe periphery of the sealant. By doing so, the process of manufacturingthe liquid crystal display panel assembly maybe simplified, and theliquid crystal display device may not have the edge stain defects whichoccur around the sealant.

Materials of sealant which is cured at the wavelength of about 400 nm ormore will be described in detail below. For example, a sealant which iscured at the wavelength of about 400 nm or more includes a resincomprised of an acryl-epoxy hybrid resin, an acryl resin and an epoxyresin, a hardener comprised of diamine, a coupling agent comprised ofsilane, a photo initiator comprised of oxime ester and a fillercomprised of silica and acryl particles. According to an exemplaryembodiment of the present invention, a sealant which is cured at thewavelength of about 400 nm or more may include, for example, oximeester-based photo initiator.

For example, an acryl-epoxy hybrid resin, an acryl resin and an epoxyresin form a main chain of a sealant, and serve as a prepolymer. Anacryl-epoxy hybrid resin may be, for example, a diphenylpropylacryl-epoxy hybrid resin represented by the following formula S-I, anacryl resin may be a diphenylpropyl acryl resin represented by thefollowing formula S-II, and an epoxy resin may be a diphenylpropyl epoxyhybrid resin represented by the following formula S-III.

A diamine reacts with an epoxy resin to be cured, decreasing thecontamination of a sealant. A diamine may be, for example,octanedihydrazide, and may be represented by the following formula S-IV.

A silane improves the adhesion of filler and organic or inorganicmaterials. A silane may be, for example,trimethoxy[3-(oxiranylmethoxy)propyl]silane, and may be represented bythe following formula S-V.

An oxime ester is a photo initiator which cures a prepolymer. An oximeester may be, for example, 4-acetyldiphenyl sulfide oxime ester (Ciba,IRGACURE OXE01, OXE02), and may be represented by the following formulaS-VI. An oxime ester can be cured at a wavelength of about 400 nm ormore, and can also be cured by visible light.

An oxime ester according to exemplary embodiment of the presentinvention can be represented by, for example, the following formulaS-VII.

where X may be any one selected from 4-acetyldiphenyl sulfide,N-ethylcarbazole and 2′-methylphenonyl n-ethylcarbazole, which can berepresented by the following formula S-VII-X1, S-VII-X2 and S-VII-X3,respectively. Y and Z each may be alkyl group (CnH2n+1), where n may bean integer of 1 to 12. Z may be phenyl.

Acryl particles decrease internal stress of a sealant, increase adhesionstrength and prevent the liquid crystal from being eluted from theresin. Acryl particles may be, for example, an acryl resin, and may berepresented by the following formula S-VIII.

Silica may decrease coefficient of heat expansion and hygroscopicity ofa sealant, and increase strength of a sealant. Silica may be, forexample, silica dioxide (SiO2).

According to an exemplary embodiment of the present invention, a sealantwhich is cured by light with a wavelength of about 400 nm or more may becomprised of, for example, diphenylpropyl acryl-epoxy hybrid resin ofabout 13 wt % to about 19 wt % (e.g., about 16 wt %), diphenylpropylacryl resin of about 39 wt % to about 49 wt % (e.g. about 44 wt %),diphenylpropyl epoxy hybrid resin of about 2 wt % to about 7 wt % (e.g.,about 4.5 wt %), octanedihydrazide of about 2 wt % to about 6 wt %(e.g., about 4 wt %), trimethoxy[3-(oxiranylmethoxy)propyl]silane ofabout 0.75 wt % to about 1.75 wt % (e.g., about 1.25 wt %,4-acetyldiphenyl sulfide oxime ester (Ciba, IRGACURE OXE01, OXE02) ofabout 0.75 wt % to about 1.75 wt % (e.g., about 1.25 wt %), silicadioxide (SiO2) of about 13 wt % to about 19 wt % (e.g., about 16 wt %),and acryl resin of about 10 wt % to about 16 wt % (e.g., about 13 wt %).

In accordance with an exemplary embodiment of the present invention, theprocess of manufacturing the liquid crystal display panel assembly 300including the sealant cured in the light having a wavelength of about400 nm or more is simplified. In addition, the liquid crystal displaydevice may not have the edge stain defects occurring around the sealant.Furthermore, because it is not necessary to form the sealant on theinner regions of the display panels 100 and 200 apart from the edges toreduce the edge stains and the sealant may be formed on the innerregions of the display panels 100 and 200 or formed close to the innerregions, the width of the outer regions of the liquid crystal displaydevice can be narrower than the conventional liquid crystal displaydevice's width by, for example, about 0.3 mm to about 1.5 mm.

The sealant hardened in the light having a wavelength of about 400 nm ormore according to an exemplary embodiment of the present invention maybe applied to the liquid crystal display panel assembly manufacturingmethods described above or below in connection with FIGS. 6A, 6B and 6C,e.g., to the SVA mode, SC-VA mode, and polarized UV-VA mode.

A liquid crystal display panel assembly manufactured by lower and uppermother-glass (not shown) display panels according to an exemplaryembodiment of the present invention will be described in detail. Anexposure voltage is stably supplied to the mother-glass assembly inwhich a plurality of liquid crystal display panel assemblies areincluded according to an exemplary embodiment of the present invention,thus reducing the manufacturing time of the liquid crystal display panelassemblies and enabling mass production thereof.

The lower mother-glass display panel according to an exemplaryembodiment of the present invention has a plurality of lower displaypanels 100, and the upper mother-glass display panel has a plurality ofupper display panels 200. It will be understood by those of ordinaryskill in the art that the lower or upper mother-glass display panel mayhave a different number of display panels according to the size of thelower or upper display panels. Except that one assembled mother-glassdisplay panel has a plurality of liquid crystal display panelassemblies, the method of manufacturing one liquid crystal display panelassembly is substantially similar to the SVA mode or SC-VA mode-basedmanufacturing methods described above in connection with FIGS. 6A and6B. Therefore, in a description of a method for manufacturing a liquidcrystal display panel assembly using the mother-glass display panel, theduplicate description of the SVA mode or SC-VA mode-based manufacturingmethod will be omitted or simplified. The rest of the features of themethod for manufacturing a liquid crystal display panel assembly usingthe mother-glass display panel according to an exemplary embodiment ofthe present invention will be described in detail.

The lower mother-glass display panel having a plurality of lower displaypanels 100 and the upper mother-glass display panel having a pluralityof upper display panels 200 are manufactured by a manufacturing methodsubstantially similar to the aforementioned manufacturing method for thelower display panel 100 and the upper display panel 200. Themother-glass display panel manufactured and assembled by the SVA mode orSC-VA mode-based manufacturing methods described above in connectionwith FIGS. 6A and 6B is annealed as described above. The assembledmother-glass display panel is comprised of a lower mother-glass displaypanel and an upper mother-glass display panel, and includes a pluralityof assembled liquid crystal display panels.

After the annealing, to apply exposure voltages to the pixel electrodesand the common electrodes of a plurality of assembled liquid crystaldisplay panels, the lower mother-glass display panel of the assembledmother-glass display panel is, for example, partially cut at one or moresides. In other words, a horizontal or vertical side of the lowermother-glass display panel is cut so that the lower mother-glass displaypanel is, for example, smaller in size than the upper mother-glassdisplay panel by about 10 mm. As the upper mother-glass display panel isgreater than the lower mother-glass display panel by about 10 mm, acommon electrode layer formed on the upper mother-glass display panel isexposed. The exposed common electrode layer has a common voltageapplying trimming pattern and a pixel voltage applying trimming pattern.The common voltage applying trimming pattern and the pixel voltageapplying trimming pattern may be formed in a prior process by a methodsuch as, for example, laser trimming. The common voltage applyingtrimming pattern is connected to common electrodes of respectiveassembled liquid crystal display panels, and the pixel voltage applyingtrimming pattern is connected to pixel electrodes of respectiveassembled liquid crystal display panels.

The exposure voltages are applied to the trimming patterns on theexposed common electrode layer. In other words, a common electrodevoltage is applied to the common voltage applying trimming pattern, anda pixel voltage is applied to the pixel voltage applying trimmingpattern. The exposure voltages are supplied by, for example, the DCvoltage or multi-step voltage supply methods described above inconnection with FIGS. 7A and 7B. In accordance with an exemplaryembodiment of the present invention, the common voltage applyingtrimming pattern and the pixel voltage applying trimming pattern mayreceive, for example, a voltage of about 0V and a voltage of about 9V toabout 25V, alternately. In other words, a voltage of about 0V and avoltage within a range of about 9V to about 25V are applied to thecommon voltage applying trimming pattern and the pixel voltage applyingtrimming pattern, swinging at a frequency of about 0.05 Hz to about 5Hz. For example, a voltage of about 0V and a voltage of about 10V mayswing at a frequency within a range of about 0.05 Hz to about 1 Hz,while a voltage of 0V and a voltage of about 20V may swing at afrequency within a range of about 0.05 Hz to about 5 Hz. A time betweencycles may fall within a range of, for example, about 0 ms to about 5ms. The applied exposure voltages are, for example, simultaneouslysupplied to the pixel electrodes and common electrodes constituting theplurality of liquid crystal display panels. As the exposure voltages areapplied to the trimming patters of the mother-glass display panelsconnected to the pixel electrodes and common electrodes of the pluralityof liquid crystal display panel assemblies, the manufacturing processmay be simple and the uniform exposure voltages may be applied to theplurality of liquid crystal display panel assemblies. Thereafter, themethods of forming the photo hardening layers 35 and 36 having apre-tilt angle by irradiating UV to the liquid crystal display panelassembly are performed, and these methods are substantially similar tothe SVA mode or SC-VA mode-based manufacturing methods described abovein connection with FIGS. 6A and 6B. The completed liquid crystal displaypanel assemblies are each separated from the mother-glass displaypanels.

By supplying the exposure voltages to the mother-glass display panelsaccording to an exemplary embodiment of the present invention, the imagequalities of the liquid crystal display panel assemblies are uniform anda lot of the liquid crystal display panel assemblies can be manufacturedin a short time.

To reduce the signal delay and the deviation between voltages applied tothe pixel electrodes and common electrodes of the liquid crystal displaypanel assemblies which are formed on the mother-glass display panels andthen assembled according to an exemplary embodiment of the presentinvention, cut portions of the lower mother-glass display panel may beon two or more sides facing each other.

In accordance with an exemplary embodiment of the present invention, thepixel voltage applying trimming pattern may be electrically connected tothe pixel electrodes by an electric conductor applied during forming ofthe upper-plate common voltage applying point, in the process of formingthe upper-plate common voltage applying point.

Polarized UV-VA Mode

Now, a method for manufacturing the liquid crystal display panelassembly 300 based on the polarized UV-VA mode will be described withreference to FIG. 6C. FIG. 6C is a schematic flowchart illustrating amethod for manufacturing the liquid crystal display panel assembly 300based on the polarized UV-VA mode using the lower and upper displaypanels 100 and 200 manufactured with reference to FIG. 1 to FIGS. 5A and5B. The method for manufacturing the liquid crystal display panelassembly 300 based on the polarized UV-VA mode is similar to the methodfor manufacturing the liquid crystal display panel assembly 300 based onthe SVA mode or the SC-VA mode except for how to form the alignmentfilms 291 and 292. Therefore, duplicate descriptions will be omittedexcept for how to form the alignment films 291 and 292 of the instantexemplary embodiment. Further, the difference between the polarizedUV-VA mode and other modes will be described in detail. In addition,since the lower-plate and upper-plate alignment films 291 and 292 aresubstantially the same in their forming process, a forming process ofthe lower-plate alignment film 291 will be described in detail to avoidduplicate description.

Manufacturing the lower display panel 100 with the pixel electrode 191and the upper display panel 200 with the common electrode 270 in firststeps S310 and S320 is substantially the same as that described inconjunction with FIG. 1 to FIGS. 5A and 5B. The pixel electrode 191 andthe common electrode 270 may not have the aforementioned micro branches197 or micro slits 199.

In the next steps S331 and S332, a polarized alignment reactant (notshown) is applied onto each of the pixel electrode 191 and the commonelectrode 270, and then undergoes, for example, Micro Phase Separation(MPS) into a vertical photo alignment material layer (not shown) and apolarized main alignment material layer (not shown), by heat. Afterpolarized UV is irradiated to the MPS-separated polarized alignmentreactants, the lower-plate and upper-plate alignment films 291 and 292having directionality are formed. Now, the forming process of thelower-plate alignment film 291 will be described in detail.

The polarized alignment reactant is made of, for example, a verticalphoto alignment material and a polarized main alignment material. Thepolarized alignment reactant is applied onto the electrodes 191 and 270by, for example, an inkjet or roll printing process, and thenMPS-separated by a hardening described below. The hardening for MPS mayproceed in, for example, two steps. First, for example, pre-heating, ora pre-bake process, proceeds at about 60° C. to about 90° C. (e.g., atabout 80° C.), for about 1 minute to about 5 minutes (e.g., about 2minutes to about 3 minutes) to remove a solvent of the polarizedalignment reactant, and then post-heating, or a post-bake process,proceeds at about 200° C. to about 240° C., (e.g., about 220° C.), forabout 10 minutes to about 60 minutes (e.g., about 10 minutes to about 20minutes), thereby forming an MPS structure. After the polarizedalignment reactant undergoes MPS, the vertical photo alignment materialforms a vertical photo alignment material layer (not shown) mainly inthe vicinity of the liquid crystal layer 3, and the polarized mainalignment material forms a polarized main alignment material layer (notshown) mainly in the vicinity of the pixel electrode 191. The polarizedmain alignment material layer MPS-separated by hardening becomes themain alignment films 33 and 34. The lower-plate main alignment film 33may be, for example, about 1000 Å thick. Therefore, the closer it getsto the liquid crystal layer 3, the higher the molarity of the verticalphoto alignment material is compared with that of the polarized mainalignment material.

The mixing wt % ratio of a vertical photo alignment material and apolarized main alignment material constituting the polarized alignmentreactant may be, for example, about 5:95 to 50:50 (e.g., about 10:90 to30:70). A solvent was not included in the composition ratio of apolarized alignment reactant. As the less vertical alignment materialsmixed in a polarized alignment reactant are the less uncured photoreactive groups, afterimage of a liquid crystal display device isreduced, and the efficiency of reaction is increased, as well. Forexample, vertical photo alignment materials may be mixed in aconcentration of about 50 wt % or less therein. In addition, if verticalphoto alignment materials are mixed in a concentration of, for example,about 5 wt % or more therein, better pre-tilt uniformity can beobtained, and thus stains in the liquid crystal display device can bereduced. The surface tension of vertical photo alignment materials andpolarized main alignment materials is, for example, about 25 to 65dyne/cm, respectively. Surface tension of vertical photo alignmentmaterial should be, for example, equal to or less than that of polarizedmain alignment material to accomplish more sharp MPS.

Vertical photo alignment material is polymeric material having aweight-average molecular weight of, for example, about 1,000 to about1,000,000, and is a compound having, for example, a main chain to whichat least one side chain is linked, the side chain comprising a flexiblefunctional group, a thermoplastic functional group, a photo reactivegroup, a vertical functional group and the like.

A flexible or thermoplastic functional group is a functional group thatfacilitates side chain linked to main chain of polymer to be aligned,and can be comprised of, for example, substituted or unsubstituted alkylor alkoxy group having about 3 to 20 carbon atoms.

A photo reactive group is a functional group that directly undergoesphoto dimerization or photo isomerization by irradiation of light suchas, for example, UV. For example, a photo reactive group is comprised ofat least one selected from azo group compounds, cinnamate groupcompounds, chalcone group compounds, coumarin group compounds, maleimidegroup compounds and combinations thereof.

A vertical functional group serves as a group which immigrates the wholeside chain to be perpendicular to the main chain placed parallel tosubstrates 110 and 210, and may be comprised of, for example, aryl groupsubstituted with alkyl group or alkoxy group having about 3 to 10 carbonatoms or cyclohexyl group substituted with alkyl group or alkoxy grouphaving about 3 to 10 carbon atoms.

For example, monomers of diamine and the like, linked with a flexiblegroup, a photo reactive group, vertical functional group and the like,are polymerized with acid anhydride and the like to form a verticalphoto alignment material. For example, diamine, of which at least one ofside chain including fluorine, aryl group and cinnamate is substituted,is polymerized with acid anhydride to form a vertical photo alignmentmaterial. Fluorine is a marker for detecting a vertical photo alignmentmaterial.

Vertical photo alignment material according to an exemplary embodimentof the present invention may be prepared by, for example, adding acompound, which is linked with thermoplastic functional group, photoreactive group, vertical functional group and the like, to polyimide,polyamic acid and the like. In this case, a side chain comprises, forexample, thermoplastic functional group, photo reactive group, verticalfunctional group and the like by direct linking thermoplastic functionalgroup with main chain of polymer.

Polarized main alignment material may comprise, for example, polymericmain chain, and its weight-average molecular weight is about 10,000 toabout 1,000,000. If an imide group is included in polarized mainalignment material in concentration of about 50-80 mol %, stains andafterimage of a liquid crystal display device can be reduced. To achievesharper MPS and reduce afterimage of a liquid crystal display device,main alignment material may comprise, for example, a vertical functionalgroup linked with a main chain of a polymer in concentration of about 5mol % or less.

Main chain may be comprised of, for example, at least one selected frompolyimide, polyamic acid, polyamide, polyamicimide, polyester,polyethylene, polyurethane, polystyrene, and mixtures thereof. As mainchain comprises more cyclic structures of imide (e.g., as main chaincomprises imide group preferably in concentration of about 50 mol % ormore), its rigidity may be higher. Thus, stains which may occur in caseof long-term driving a liquid crystal display device, is reduced, andthus alignment stability of liquid crystal molecules will be better.

The polarized main alignment material may correspond to the surface mainalignment material in the SC-VA mode. In addition, it will be understoodthat the polarized main alignment material may be a material used formaking the VA mode or the TN mode devices.

If UV is irradiated to the MPS-separated vertical photo alignmentmaterial layer, a photo-reactive group is light-hardened, therebyforming the photo hardening layer 35. The main alignment film 33 formedby thermal hardening and the photo hardening layer 35 formed by UVconstitute the lower-plate alignment film 291.

The light irradiated to the vertical photo alignment material layer maybe, for example, polarized UV, collimated UV, or slanted light. Thepolarized UV may be, for example, Linearly Polarized Ultra Violet (LPUV)or Partially Polarized Ultra Violet (PPUV). The irradiated wavelengthmay be, for example, about 270 nm to about 360 nm, and the irradiatedenergy may be about 10 mJ to about 5,000 mJ. A mask provided with anopening portion transmitting light and a light blocking portion blockinglight is placed to correspond to a photo hardening region or a non-photohardening region on the lower or upper display panel 100 and 200, andthen light is irradiated thereto. In accordance with an exemplaryembodiment of the present invention, the LPUV is irradiated at apredetermined tilt angle, e.g., about 20° to about 70°, with respect tothe substrates 110 and the 210 of the display panels 100 and 200. Thevertical photo alignment material layer undergoes a dimerizationreaction, cis-trans isomerization, or light-decomposition reaction bythe light passing through the opening portion in the mask. Therefore,the polymer of the photo hardening layer 35 light-hardened according tothe LPUV's direction and the polarization direction has a direction thatis slightly tilted with respect to the direction perpendicular to thesubstrate 110.

This gives the same effect as if the surfaces of the alignment films 291and 292 have been rubbed in a specific direction. The liquid crystalmolecules 31 adjacent to the photo hardening layer 35 are tilted similarto the polymer of the photo hardening layer 35, having a pre-tilt angleof a specific angle. Therefore, depending on the tilt angle of polarizedUV, a direction of the pre-tilt angle of the liquid crystal molecules 31is determined and a domain having liquid crystal molecules 31 aligned ina specific pre-tilt direction is formed. According to an exemplaryembodiment of the present invention, photo hardening layers 35 and 36having two pre-tilt angle directions are formed on each of the lower andupper display panels 100 and 200, and the liquid crystal layer 3 of theliquid crystal display device has four domains, which have differentazimuths in the pre-tilt angles of the photo hardening layers 35 and 36by the vector sum. On the other hand, the photo hardening layers 35 and36 having four different directions may be formed on any one of thelower and upper display panels 100 and 200, so that the liquid crystallayer 3 may have, for example, four domains. Azimuths of the fourdomains may be tilted, for example, about 45° with respect to thepolarization axis of the polarizer.

In the next step S340, a sealant is formed between the lower and upperdisplay panels 100 and 200 on which the lower-plate and upper-platealignment films 291 and 292 are formed, respectively, and the twodisplay panels 100 and 200 are sealed, thereby manufacturing the liquidcrystal display panel assembly 300. The manufactured liquid crystaldisplay panel assembly 300 has characteristics of the polarized UV-VAmode. If the liquid crystal display device is manufactured based on thepolarized UV-VA mode, the non-hardened photo-reactive group is reduced,contributing to a reduction in afterimage of the liquid crystal displaydevice. In addition, domains are formed depending on the direction ofthe polarized UV, improving processability of the liquid crystal displaydevices. In other words, in the SVA mode or the SC-VA mode, the liquidcrystal molecules 31 have a pre-tilt angle according to the electricfield, which is formed in the liquid crystal layer 3 by an exposurevoltage, and the direction of the micro branches 197, but in thepolarized UV-VA mode, the photo hardening layer 35 is formed beforesealing of the two display panels 100 and 200 regardless of theexistence and direction of the micro branches 197, thereby increasingthe processability.

An alignment film of a liquid crystal display device according to anexemplary embodiment of the present invention is formed by, for example,a polarized alignment reactant having a mixed photo alignment material48. The mixed photo alignment material 48 contained in the polarizedalignment reactant according to an exemplary embodiment of the presentinvention easily moves to the surface of the polarized alignmentreactant in the phase separation process, thus reducing the non-hardenedphoto-reactive polymer, and reducing the production cost, the RDCvoltage, or the afterimages of the liquid crystal display device. Themixed photo alignment material 48 according to an exemplary embodimentof the present invention includes, for example, a heat-reactive part 48a, a photo-reactive part 48 b, and a vertical functional part 48 c (seeFIGS. 15A-G), and may be a compound thereof.

This exemplary embodiment of the present invention is substantiallysimilar to the exemplary embodiment of the liquid crystal display panelassembly manufactured by the aforementioned polarized UV-VA mode exceptfor the materials constituting the polarized alignment reactant and theMPS process in the thermal curing process. A duplicate description willbe simplified or omitted. Since the lower-plate and upper-platealignment films 291 and 292 are formed in a substantially similar way,the forming process of the alignment film according to the currentexemplary embodiment of the present invention will be described withoutdistinguishing between the alignment films 291 and 292.

Now, reference will be made to FIGS. 15A to 15G to give a detaileddescription of a forming process for an alignment film formed by apolarized alignment reactant 47 having the mixed photo alignmentmaterial 48 according to an exemplary embodiment of the presentinvention. FIGS. 15A to 15G illustrate a sequential process of formingan alignment film of a liquid crystal display panel assembly of anotherUV-VA mode according to an exemplary embodiment of the presentinvention. Referring to FIG. 15A, the polarized alignment reactant 47having the mixed photo alignment material 48 is applied onto the pixelelectrode 191 and the common electrode 270 as described above. Thepolarized alignment reactant 47 having the mixed photo alignmentmaterial 48 is, for example, formed on inner regions of the lower andupper display panels 100 and 200, or may be applied on outer regionsthereof in a partially overlapping manner. The polarized alignmentreactant 47 having the mixed photo alignment material 48 may be may be amixture of for example, a polarized main alignment material 37, a photoalignment vertical material 49, the mixed photo alignment material 48,and a solvent. The pixel electrode 191 and the common electrode 270 maynot have the aforementioned micro branches 197 or micro slits 199.

Now, a detailed description will be made of a composition ratio of thepolarized main alignment material 37, the photo alignment verticalmaterial 49, the mixed photo alignment material 48, and the solventconstituting the polarized alignment reactant 47 having the mixed photoalignment material 48.

Solid contents prepared by including photo alignment vertical material49, polarized main alignment material 37 and mixed photo alignmentmaterial 48 are dissolved in a solvent to form polarized alignmentreactant 47 including mixed photo alignment material 48. Theconcentration of solvent in polarized alignment reactant 47 may be, forexample, about 85 wt % to about 98 wt % (e.g., about 93.5 wt %), and theconcentration of solid contents except for solvent, e.g., thecombination of mixed photo alignment material 48, polarized mainalignment material 37 and photo alignment vertical material 49 may beabout 2 wt % to about 15 wt % (e.g., about 6.5 wt %) in polarizedalignment reactant 47. The solid contents in concentration of, forexample, about 2 wt % or more can contribute to enhancing theprintability of the polarized alignment reactant 47 when applied to theupper display panel. The solid contents in concentration of, forexample, about 15 wt % or less can contribute to preventing from thegeneration of precipitates formed by undissolved solid contents insolvent, and make the printability of polarized alignment reactant 47good.

The concentration of polarized main alignment material 37 in solidcontents may be, for example, about 34 wt % to about 89.55 wt % (e.g.,about 70 wt %), the concentration of photo alignment vertical material48 may be about 8.5 wt % to about 59.7 wt % (e.g., about 30 wt %), andthe concentration of mixed photo alignment material 48 may be about 0.5wt % to about 15 wt % (e.g., about 5 wt %). Solid contents are polarizedalignment reactant 47 except for solvent. Mixed photo alignment material48 of which concentration is, for example, about 0.5 wt % or more intotal weight of solid contents can react with photo alignment verticalmaterial 49 to introduce minimal photo reactivity into photo alignmentvertical material 49. Mixed photo alignment material 48 of whichconcentration is, for example, about 15 wt % or less in total weight ofsolid contents can minimize the decrease in alignment property ofalignment film formed by polarized alignment reactant 47.

The weight ratio of photo alignment vertical material 49 versuspolarized main alignment material 37 may be, for example, about 1:9 toabout 6:4 (e.g. about 1:9 to about 5:5). Polarized alignment reactant 47having this weight ratio can be readily phase-separated after theabove-described pre-heating or heating process, and mixed photoalignment vertical material 49 can be readily moved to the surface ofpolarized alignment material 47 which is in contact with the air. Photoalignment vertical material 49 and polarized main alignment material 37may have a weight-average molecular weight of, for example, about 10,000to about 900,000 for storage property and printability of materials. Aweight-average molecular weight is a conversed value of monodispersepolystyrene assessed by gel permeation chromatography (GPC).

Polarized main alignment material 37, photo alignment vertical material49, mixed photo alignment material 48 and solvents, which constitutepolarized alignment reactant 47 including mixed photo alignment material48 will be described in detail below.

Polarized main alignment material 37 is a compound comprised of, forexample, monomers which have no side chain and concentration of about 95mol % to about 100 mol % and monomers which have side chain andconcentration of about 0 mol % to about 5 mol %, and polarized mainalignment material 37 having the composition ratio has horizontalalignment property. For example, a monomer which has no side chain maybe about 100 mol % in polarized main alignment reactant 37, but may bein the composition range which does not decrease horizontal alignmentproperty, e.g., about 95 mol % to about 100 mol %. In addition, monomerswhich have side chain may be in the composition range which does notdecrease horizontal alignment property, e.g., about 0 mol % to about 5mol % in polarized main alignment reactant 37. Side chain of monomersconstituting polarized main alignment material 37 may include, forexample, all of functional groups other than—H. Side chain of monomersconstituting surface main alignment material 37 may be, for example,substantially equal to that of monomers constituting photo alignmentvertical material 49, but polarized main alignment material 37 may havehorizontal alignment property as this composition ratio of monomershaving a side chain is low.

Polarized main alignment material 37 may be, for example, at least oneselected from polyimide-based compound, polyamic acid-based compound,polysiloxane-based compound, polyvinylcinnamate-based compound,polyacrylate-based compound, polymethylmethacrylate-based compound, andmixtures thereof.

According to an exemplary embodiment of the present invention, ifpolarized main alignment material 37 is a polyimide-based compound, mainchain of this compound may be a monomer having an imide bond.

Photo alignment vertical material 49 is a compound comprised of, forexample, monomers of which end is linked with side chains having ahydrophobic group and monomers which have no side chain. Monomers whichhave side chains constituting photo alignment vertical material 49 maybe, for example, 10 mol % to 70 mol % (e.g., about 20 mol % to about 60mol %), and monomers which have no side chain may be, for example, 30mol % to 90 mol % (e.g., about 40 mol % to about 80 mol %). Photoalignment vertical material 49 having this composition ratio hasvertical alignment property.

Monomers with side chains and monomers with no side chain, constitutingphoto alignment vertical material 49, may be, for example, at least oneselected from monomers of imide bond which constitute polyimide-basedcompounds, amic acid group monomers which constitute polyamic acid-basedcompounds, siloxane group monomers which constitute polysiloxane-basedcompounds, vinylcinnamate group monomers which constitutepolyvinylcinnamate-based compounds, acrylate group monomers whichconstitute polyacrylate-based compounds, methyl methacrylate groupmonomers which constitute polymethylmethacrylate-based compounds, andmixtures thereof.

Main chain of photo alignment vertical material 49 may be, for example,polyimide-based compounds or polyamic acid-based compounds. According toan exemplary embodiment of the present invention, photo alignmentvertical material 49 comprised of monomers of imide bond includes, forexample, polyimide-based compounds as a main chain, and has a structureof which a side chain is linked to a main chain. Photo alignmentvertical material 49 comprised of monomers of imide bond may be preparedby, for example, imidation of a part of polyamic acid-based compounds. Amain chain of photo alignment vertical material 49 is defined as alinking part of monomers other than side chain. According to anexemplar), embodiment of the present invention, photo alignment verticalmaterial 49 which comprises polyamic acid-based compounds as a mainchain can be prepared by, for example, reaction of diamine-basedcompounds with acid anhydride. Diamine-based compounds may be diaminehaving substantially the same functional groups as side chains.

Side chains of photo alignment vertical material 49 have the firstfunctional group, the second functional group linked with the firstfunctional group and including a large number of cyclic carbon atoms,and a vertical functional group 49 c linked with the second functionalgroup. The first functional group may comprise, for example, alkyl groupor alkoxy group having 1 to 10 carbon atoms. The second functional groupis linked with a main chain by the first functional group, and linkedwith a vertical functional group 49 c. The second functional group maycomprise, for example, cyclohexane, benzene, chroman, naphthalene,tetrahydropyran, and dioxane or steroid derivatives. A verticalfunctional group 49 c shown in FIG. 15C is a hydrophobic group which islinked with the end of a side chain. A vertical functional group 49 cmay comprise, for example, a linear type or a branched type, of whichside chain is linked with linear type, of alkyl group having 1 to 12carbon atoms or an alkenyl group having 2 to 12 carbon atoms. Hydrogenatoms in a vertical functional group 49 c may be substituted by, forexample, F or Cl.

According to an exemplary embodiment of the present invention, a sidechain of photo alignment vertical material 49 may be a monomerrepresented by, for example, the following formula X-UV1 to X-UV4.

According to an exemplary embodiment of the present invention, a sidechain of photo alignment vertical material 49 may comprise, for example,a photo-reactive part having a photo-reactive group. A photo-reactivegroup linked to a side chain of photo alignment vertical material 49 maybe cured by light to form a photo hardening layer having a pre-tiltangle. A photo-reactive part may be replaced with, for example, thesecond functional group, which is placed between the first functionalgroup and a vertical functional group 49 c, to be linked with the firstfunctional group and a vertical functional group 49 c. Unlike this, aphoto-reactive part may be, for example, placed between the firstfunctional group and the second functional group to be linked with thefirst and second functional groups, respectively. A photo-reactive partlinked with the side chain of a photo alignment vertical material 49 maybe monomers represented by, for example, the following formulas X-UV5 toX-UV9.

A photo-reactive part linked to a side chain of photo alignment verticalmaterial 49 may be, for example, at least one selected from theabove-described photo-reactive polymer, reactive mesogen,photo-polymerizable material, photo-isomerizable material, andcombinations or mixtures thereof.

Mixed photo alignment material 48 according to the present inventionincludes a compound represented by, for example, the following formulaX-UP1. Mixed photo alignment material 48 is comprised of, for example, aheat-reactive part 48 a, a photo-reactive part 48 b, a linking part anda vertical functional part 48 c. A carbon-carbon bond in a heat-reactivepart 48 a is cleaved by heat, and facilitates photo alignment verticalmaterial 49 and mixed photo alignment material 48 to be linked to eachother. A photo-reactive part 48 b is linked with any otherphoto-reactive part by light. A linking part connects a photo-reactivepart 48 b with a heat-reactive part 48 a and a vertical functional part48 c. A vertical functional part 48 c increases vertical alignmentproperty of mixed photo alignment material 48.B₁—X₁-A₁-Y₁-D  Formula X-UP1

where A₁ is a photo-reactive part 48 b of mixed photo alignment material48 depicted in FIG. 15C. A photo-reactive part 48 b may be polymerizedor cured with adjacent photo-reactive part 48 b by irradiation of light.A₁ may be cinnamate, coumarin or chalcone.

X₁ and Y₁ are a linking part, and connect a photo-reactive part A₁ witha heat-reactive part B₁ and a vertical functional part D. X₁ and Y₁ eachmay be a single bond or —C_(n)H_(2n)— (where n is an integer of 1 to 6).If X₁ and/or Y₁ is —C_(n)H_(2n)—, —X₁ and/or Y₁ may have a linear typeor a branched type hydrocarbon. One or more of —CH₂— constituting X₁ orY₁ may be substituted by —O— or —Si—, respectively. According to anexemplary embodiment of the present invention, X₁ and/or Y₁ may be—CH₂—, —CH₂—CH₂—, —O—CH₂—, —CH₂—Si— or —O—Si—O—.

B₁ is a heat-reactive part 48 a depicted in FIG. 15C. B₁ is comprised ofcarbon-oxygen bond which is easily cleaved by heat, and can be easilylinked with photo alignment vertical material 49. B₁ may be

D is a vertical functional part 48 c of mixed photo alignment material48 having vertical alignment property depicted in FIG. 15C, and is alkylgroup having 1 to 12 carbon atoms or alkenyl group having 2 to 12 carbonatoms. A vertical functional part 48 c of mixed photo alignment material48 increases vertical alignment property. For example, mixed photoalignment material 48 includes a vertical functional part 48 c otherthan a vertical functional group 49 c linked to a side chain of photoalignment vertical material 49, and thus the number of verticalfunctional groups constituting polarized alignment reactant 47 isincreased. Therefore, mixed photo alignment material 48 having avertical functional part 48 c and photo alignment vertical material 49having a vertical functional group 49 c are linked to each other by, forexample, a heat curing process to increase the density of a verticalalignment functional group, and can improve vertical alignment propertyof alignment film. Hydrogen atoms other than B₁ in formula X-UP1 eachmay be substituted by, for example, F or Cl.

According to an exemplary embodiment of the present invention, mixedphoto alignment material 48 represented by, for example, formula X-UP1has cinnamate which constitutes A₁, —O—Si—O— which constitutes X₁ andY₁, respectively,

which constitutes B₁, and

which constitutes D.

According to an exemplary embodiment of the present invention, mixedphoto alignment material 48 may include a compound represented by, forexample, the following formula X-UP2.B₂—X₂-A₂  Formula X-UP2

where A₂ may be materials constituting a photo-reactive part 48 b of theabove-described mixed photo alignment material 48, X₂ may be materialsconstituting a linking part of the above-described mixed photo alignmentmaterial 48, and B₂ may be materials constituting a heat-reactive part48 a of the above-described mixed photo alignment material 48. In theformula X-UP2, hydrogen atoms other than B₂ may be substituted by, forexample, F or Cl.

Compared with the mixed photo alignment material 48 expressed by FormulaX-UP1, the mixed photo alignment material 48 expressed by Formula X-UP2does not have the vertical functional part 48 c. Although the mixedphoto alignment material 48 expressed by Formula X-UP2 does not have thevertical functional part 48 c, the large size of the photo-reactive part48 b enables stable arrangement of the side chains of the photoalignment vertical material 49.

The solvent may be, for example, a compound for facilitating dissolutionor mixing of the photo alignment vertical material 49, the polarizedmain alignment material 37, and the mixed photo alignment material 48,or a compound capable of increasing the printability thereof. Thesolvent may be, for example, an organic solvent, or may be one of theaforementioned solvent materials.

To increase the photo hardening reaction, the polarized alignmentreactant 47 may further include the aforementioned photoinitiator.

Referring to FIGS. 15B to 15E, after being applied, the polarizedalignment reactant 47 is, for example, thermally cured by pre-heating(FIG. 15B) or post-heating (FIG. 15D) as described above. The polarizedalignment reactant 47 undergoes MPS by the thermal curing. In accordancewith an exemplary embodiment of the present invention, the polarizedalignment reactant 47 undergoes phase separation in the pre-heatingstep, and the phase separation is completed in the post-heating step.Now, the phase separation process for the polarized alignment reactant47 will be described in detail.

Referring to FIG. 15B, the polarized alignment reactant 47 ispre-heated. The pre-heated polarized alignment reactant 47 isMPS-separated into a polarized main alignment material layer 37 a and avertical photo alignment material layer 46 a, and the solvent of thepolarized alignment reactant 47 is, for example, vaporized. Thepolarized main alignment material layer 37 a is formed, for example,close to the pixel electrode or the common electrode, and primarilycontains the polarized main alignment material 37. The polarized mainalignment material layer 37 a may contain, for example, the photoalignment vertical material 49 and the mixed photo alignment material48. The vertical photo alignment material layer 46 a is formed, forexample, close to the surface contacting air, and primarily contains thepolarized main alignment material 37 and the mixed photo alignmentmaterial 48. The vertical photo alignment material layer 46 a maycontain, for example, the polarized main alignment material 37. Thephoto alignment vertical material 49 and the polarized main alignmentmaterial 37 might be substantially mixed in the interface between thepolarized main alignment material layer 37 a and the vertical photoalignment material layer 46 a.

Referring to FIG. 15C, the polarized alignment reactant 47 isphase-separated as follows. In accordance with an exemplary embodimentof the present invention, the photo alignment vertical material 49constituting the polarized alignment reactant 47 has a non-polaritycompared with the polarized main alignment material 37, while thepolarized main alignment material 37 has a polarity compared with thephoto alignment vertical material 49. In addition, air has anon-polarity compared with the material constituting the pixel or commonelectrode, while the material constituting the pixel or common electrodehas a polarity compared with air. Hence, in the pre-heating process, thephoto alignment vertical material 49 constituting the polarizedalignment reactant 47 mostly moves in the direction of the surfacecontacting air because its affinity to air is greater than that of thepolarized main alignment material 37. In addition, as the polarized mainalignment material 37 having a polarity extrudes the mixed photoalignment material 48, the mixed photo alignment material 48 moves likethe photo alignment vertical material 49, thus being mixed with thephoto alignment vertical material 49. Hence, the mixed photo alignmentmaterial 48 and the photo alignment vertical material 49, which havemoved in the direction of the surface in the pre-heating step, form thevertical photo alignment material layer 46 a. Consequently, the mixedphoto alignment material 48 can readily move toward the surfacecontacting air by virtue of the phase separation process for thepolarized main alignment material 37 and the photo alignment verticalmaterial 49, thus reducing the content of the mixed photo alignmentmaterial 48 contained in the polarized alignment reactant 47. On theother hand, the polarized main alignment material 37 constituting thepolarized alignment reactant 47 moves toward an electrode layer becauseits affinity to the material formed on the bottom of the polarizedalignment material 47, e.g., near the pixel electrode or the commonelectrode, is greater than that of the photo alignment vertical material49. Having moved toward the electrode layer, the polarized mainalignment material 37 and some of the photo alignment vertical material49 form the polarized main alignment material layer 37 a. The verticalfunctional group 49 c of the photo alignment vertical material 49 mayhave a vertical alignment in the pre-heating. The mixed photo alignmentmaterial 48 may include, for example, the heat-reactive part 48 a, thephoto-reactive part 48 b, and the vertical functional part 48 c.

Referring to FIGS. 15D and 15E, the phase-separated polarized alignmentreactants 46 a and 37 a are post-heated as described above. Thepost-heated polarized alignment reactants 46 a and 37 a form a mainalignment film 33 and a vertical alignment. The main alignment film 33is formed mainly by, for example, curing of the polarized main alignmentmaterial 37. In the post-heating process, the chemical bond of theheat-reactive part 48 a constituting the mixed photo alignment material48 is readily broken, and the bond-broken heat-reactive part 48 a ischemically bonded to the photo alignment vertical material 49.Therefore, the photo alignment vertical material 49 constituting thevertical photo alignment material layer 46 a, and the heat-reactive part48 a of the mixed photo alignment material 48 are chemically bonded, andthe photo-reactive part 48 b and the vertical functional part 48 c forma vertical alignment on the surface of the vertical alignment materiallayer 46 a. Accordingly, even though the photo alignment verticalmaterial 49 does not have the photo reactivity, the photo alignmentvertical material 49 may have the photo reactivity by being bonded tothe heat-reactive part 48 a of the mixed photo alignment material 48.The photo alignment vertical material 49 or the polarized main alignmentmaterial 37 bonded to the mixed photo alignment material 48 can have thephoto reactivity, thus further reducing the content of the mixed photoalignment material 48 contained in the polarized alignment reactant 47.In the post-heating process, the solvent of the polarized alignmentreactant 47 may be additionally vaporized. Further, in the post-heatingprocess, the vertical functional group 49 c contained in the photoalignment vertical material 49 may be vertically aligned.

For example, after completion of the post-heating process, the polarizedalignment reactant 47 is cleaned by DIW, and may be additionally cleanedby IPA. After the cleaning, the polarized alignment reactants 47 aredried.

Now, referring to FIGS. 15F and 15G, if light is irradiated to thevertical photo alignment material layer 46 a, the photo-reactive part 48b of the mixed photo alignment material 48 is hardened, forming thephoto hardening layer 35 on the main alignment film as illustrated inFIG. 15G. The main alignment film 33 formed by heat curing and the photohardening layer 35 formed by UV light constitute the lower-platealignment film 291. The light irradiated to the vertical photo alignmentmaterial layer 46 a and the photo hardening process, shown in FIG. 15F,are the same as those described above in relation to the polarized UV-VAmode. By the non-content photo hardening process, the photo hardeninglayer has a pre-tilt angle. The pre-tilt angle of the photo hardeninglayer may be, for example, about 80° to about 90°, more preferably about87.5° to about 89.5°, with respect to the substrates of the displaypanels 100 and 200. Owing to the light irradiation method, even thoughthe pixel electrodes do not have the micro slits 199 or micro branches197, the liquid crystal display device according to an exemplaryembodiment of the present invention may have a plurality of domains,which divide the liquid crystal layer 3 into a plurality of domains.

Thereafter, as described above in relation to step S340, the liquidcrystal layer 3 and the sealant are formed between the lower and upperdisplay panels 100 and 200 on which the lower-plate and upper-platealignment films 291 and 292 are formed, respectively. The display panels100 and 200 assembled by the sealant are annealed. The material of thesealant, the process of curing the sealant, and the annealing may be thesame as those described above for the main alignment films 33 and 34having rigid vertical alignment side-chains. The liquid crystal displaypanel assembly 300 manufactured in this way has characteristics of thepolarized UV-VA mode.

According to an exemplary embodiment of the present invention, the mixedphoto alignment material 48 contained in the polarized alignmentreactant 47 can readily move toward the surface onto which light isirradiated, in the process of forming the alignment film, making itpossible to reduce the content of the mixed photo alignment material 48contained in the polarized alignment reactant 47. Therefore, theproduction cost of the liquid crystal display device may be reduced.

In addition, the photo alignment vertical material 49 or the polarizedmain alignment material 37 can have a polarity due to their combinationwith the mixed photo alignment material 48, contributing to a furtherreduction in the content of the mixed photo alignment material 48contained in the polarized alignment reactant 47.

Furthermore, the amount of the mixed photo alignment material 48remaining in the alignment film can be minimized, contributing to areduction in the RDC voltage or afterimages of the liquid crystaldisplay device.

The main alignment films 33 and 34 were formed by the polarizedalignment reactant 47 having the mixed photo alignment material 48according to an exemplary embodiment of the present invention, and theliquid crystal display device having the same was manufactured.

The polarized alignment reactant 47 applied the experiment of thepresent invention included solid contents comprising, for example,polarized main alignment material 37, photo alignment vertical material49 and mixed photo alignment material 48 and a solvent. Solid contentsconstituting polarized alignment reactant 47 were, for example, about6.5 wt %, and a solvent was about 93.5 wt %. In addition, for example,photo alignment vertical materials 49 constituting solid contents wereabout 30 wt %, polarized main alignment materials 37 were about 70 wt %,and mixed photo alignment materials 48 were about 5 wt %, in solidcontents.

Photo alignment vertical material 49 was, for example, a compound (JSR,PI-37) of diacid anhydride and diamine, which is comprised of

in a ratio of about 1:0.4:0.6, where W2 is

and W3 is

Polarized main alignment material 37 was a compound (JSR, PA-4) ofdiacid anhydride and diamine, which is comprised of

in a ratio of about 1:1, where W1 is

Mixed photo alignment material 48 was, for example, a compound (JSR,P_A(std.) represented by the following formula X-UP3.

A solvent was, for example, a mixture of N-methylpyrrolidone of about 45wt % and butyl cellosolve of about 55 wt %.

The polarized alignment reactant 47 having the above composition ratio,applied onto a 17-inch liquid crystal display panel, was, for example,pre-heated at about 80° C., and then post-heated at about 220° C. forabout 20 minutes. Thereafter, linearly polarized UV was, for example,irradiated in an anti-parallel direction to the polarized alignmentreactant 47 formed on the common electrode constituting the upperdisplay panel, while having a tilt angle of about 50° with respect tothe surface of the substrate of the display panel. In the same manner,the linearly polarized UV was irradiated to the polarized alignmentreactants 47 formed on the pixel electrodes constituting the lowerdisplay panel.

Due to the irradiated UV, the lower-plate and upper-plate photohardening layers 35 and 36 had anti-parallel pre-tilt angles. In otherwords, the photo hardening layers 35 and 36 had, for example, fourdifferent pre-tilt angles, and the liquid crystal layer 3 of the liquidcrystal display device had four domains which were formed to havedifferent azimuths by the photo hardening layers 35 and 36 having fourdifferent pre-tilt angles. The azimuths of the four domains are definedby a vector sum of the four different pre-tilt angles. An intensity ofthe linearly polarized UV was, for example, about 20 mJ/cm². Themanufactured liquid crystal display panel assembly was operated bycharge sharing-based 1G1D driving described above in conjunction withFIG. 11.

In the manufactured liquid crystal display device, liquid crystalmolecules 31 adjacent to the photo hardening layer 35/36 had a pre-tiltangle of, for example, about 88.2° with respect to the surface of thesubstrate of the liquid crystal display panel. In addition, the surfaceafterimage of the liquid crystal display device, which had been operatedin a chamber having, for example, a high temperature of about 50° C. for24 hours with an image of a check flicker pattern, showed a good levelof approximately 3.

Driving of Liquid Crystal Display Device

Now, the structure and operation of an equivalent circuit for one pixelPX of a liquid crystal display device will be described with referenceto FIG. 11. FIG. 11 is an equivalent circuit diagram of a Charge Sharing(CS) charging-based 1 1G1D for one pixel PX shown in FIG. 3 according toan exemplary embodiment of the present invention. The equivalent circuitfor one pixel PX in the liquid crystal display device includes, forexample, signal lines and a pixel PX connected thereto, the signal linesincluding a gate line 121, a storage electrode line 125, a down gateline 123, and a data line 171.

One pixel PX is comprised of, for example, first, second and third TFTsQh, Ql and Qc, first and second liquid crystal capacitors Clch and Clcl,first and second storage capacitors Csth and Cstl, and a down capacitorCstd. The first and second TFTs Qh and Ql formed on the lower displaypanel 100 are, for example, 3-terminal devices, in which their gateelectrodes or control terminals are connected to the gate line 121,their source electrodes or input terminals are connected to the dataline 171, and their drain electrodes or output terminals are connectedto the first and second liquid crystal capacitors Clch and Clcl and thefirst and second storage capacitors Csth and Cstl, respectively. Thethird TFT Qc is a 3-terminal device, in which its gate electrode or acontrol terminal is connected to the down gate line 123, its sourceelectrode or an input terminal is connected to the second liquid crystalcapacitor Clcl or the output terminal the second TFT Ql, and its drainelectrode or an output terminal is connected to the down capacitor Cstd.First and second subpixel electrodes 191 h and 191 l constituting apixel electrode 191 are connected to the drain electrodes or outputterminals of the first and second TFTs Qh and Ql, respectively.Electrodes of the first and second liquid crystal capacitors Clch andClcl are connected to the first and second subpixel electrodes 191 h and191 l, respectively, and other electrodes thereof are each connected tothe common electrode 270 on the upper display panel 200. Electrodes ofthe first and second storage capacitors Csth and Cstl are connected tothe first and second subpixel electrodes 191 h and 191 l, respectively,and other electrodes thereof are each connected to the storage electrodeline 125 on the lower display panel 100, or to the portions 126, 127 and128 connected to the storage electrode line 125. One electrode of thedown capacitor Cstd is connected to the output terminal of the third TFTQc, and another electrode thereof is connected to the storage electrodeline 125. The first and second storage electrodes Csth and Cstl mayincrease voltage maintaining abilities of the first and second liquidcrystal capacitors Clch and Clcl, respectively. The electrodes of thecapacitors Clch, Clcl, Csth, Cstl and Cstd overlap one another, with theinsulators 3, 140, 181 and 182 interposed therebetween.

Now, the charging principle of a pixel PX will be described in detail.If a gate-on voltage Von is supplied to an n-th gate line Gn, the firstand second TFTs Qh and Ql connected thereto are turned on, and agate-off voltage Voff is supplied to an n-th down gate line An.Accordingly, a data voltage on an n-th data line Dn is equally suppliedto the first and second subpixel electrodes 191 h and 191 l via thefirst and second TFTs Qh and Ql, which are turned on. As the first andsecond liquid crystal capacitors Clch and Clcl charge charges as much asvoltage differences between a common voltage Vcom on the commonelectrode 270 and the voltages on the first and second subpixelelectrodes 191 h and 191 l, respectively, the charged voltage values ofthe first and second liquid crystal capacitors Clch and Clcl are thesame. Thereafter, the gate-off voltage Voff is supplied to the n-th gateline Gn and the gate-on voltage Von is supplied to the n-th down gateline An. In other words, the first and second TFTs Qh and Ql are eachturned off, and the third TFT Qc is turned on. Thus, charges on thesecond subpixel electrode 191 l connected to the output terminal of thesecond TFT Ql flow into the down capacitor Cstd, lowering a voltage onthe second liquid crystal capacitor Clcl. As a result, though the samedata voltage is supplied to the subpixel electrodes 191 h and 191 l, thecharged voltage on the first liquid crystal capacitor Clch is greaterthan that on the second liquid crystal capacitor Clcl. A ratio of thevoltage on the second liquid crystal capacitor Clcl to the voltage onthe first liquid crystal capacitor Clch may be, for example, about 0.6to about 0.9:1 (e.g., about 0.77:1). In this manner, the first andsecond subpixel electrodes 191 h and 191 l are provided with the samedata voltage, and the second liquid crystal capacitor Clcl of the secondsubpixel electrode 191 l and the down capacitor Cstd share charges tomake capacitances of the first and second liquid crystal capacitors Clchand Clcl different from each other. This is called CS charging.

As a result, liquid crystal molecules 31 of the first subpixel electrode191 h receive an electric field of higher strength than that of liquidcrystal molecules 31 of the second subpixel electrode 191 l, so theliquid crystal molecules 31 of the first subpixel electrode 191 h aretilted more. As the liquid crystal molecules 31 of first and secondsubpixels 190 h and 190 l charged by CS compensate for phase retardationof light if they have different tilt angles, the liquid crystal displaydevice according to an exemplary embodiment of the present invention mayhave excellent side visibility and a wide reference viewing angle. Thereference viewing angle refers to a limit angle or an inter-gray levelluminance-crossing limit angle at which a side contrast ratio versus afront contrast ratio is, for example about 1/10. The wider the referenceviewing angle, the better the side visibility of the liquid crystaldisplay device may be. In addition, one gate line 121 and one data line171 are connected to one pixel PX to operate subpixels 190 h and 190 lconstituting one pixel PX, thus increasing the aperture ratio of theliquid crystal display device. This method in which one gate line 121and one data line 171 are connected to one pixel PX is 1G1D.

In an exemplary embodiment of the present invention, if the gate-onvoltage Von supplied to the n-th gate line Gn and the gate-on voltageVon supplied to the n-th down gate line An overlap due to a signal delayof the gate-on voltages, poor charging may occur in the pixel electrode.To correct this, the n-th down gate line An may, for example, beconnected to an (n+m)-th gate line 121 (where m≧1)(e.g., an (n+4)-thgate line 121) to receive the gate-on voltage Von.

A 1-pixel PX circuit according to an exemplary embodiment of the presentinvention is 2-TFT (2T) charging-based 1 Gate 2 Data (1G2D), in whichtwo TFTs and two data lines are connected to one pixel PX. In otherwords, first and second subpixel electrodes 191 h and 191 l arerespectively connected to output terminals of first and second TFTshaving gate electrodes connected to the same gate line, and twodifferent data lines are connected to input terminals of the first andsecond TFTs, respectively. Different data voltages supplied to the firstand second subpixel electrodes 191 h and 191 l via the two differentdata lines are divided voltages of a voltage corresponding to one image.The 2T charging-based 1G2D driving can apply an arbitrary data voltageto each of the subpixel electrodes 191 h and 191 l, thus furtherincreasing the side visibility of the liquid crystal display device.

An exemplary embodiment of the present invention provides a swingvoltage electrode line driving method. For example, in this drivingmethod, each pixel has two TFTs, one gate line, one data line, and twoswing voltage electrode lines. Gate electrodes of first and second TFTsare connected to the gate line, source electrodes thereof are connectedto the data line, and drain electrodes thereof are connected to firstand second subpixel electrodes and first and second storage capacitors,respectively. Electrodes of first and second liquid crystal capacitorsare connected to the first and second subpixel electrodes, respectively,and other electrodes thereof are each connected to a common electrodeformed on the upper display panel. Electrodes of the first and secondstorage capacitors are connected to the first and second subpixelelectrodes, respectively, and other electrodes thereof are connected toswing voltage electrode lines, respectively. During a pixel operation,pulse trains having a voltage level of a specific period are applied tothe swing voltage electrode lines, and opposite-phase voltages aresimultaneously applied to the swing voltage electrode line of the firstsubpixel and the swing voltage electrode line of the second subpixel.The pulse trains provided to the swing voltage electrode lines may have,for example, two different voltages. Hence, a voltage charged in afirst-subpixel liquid crystal capacitor and a voltage charged in asecond-subpixel liquid crystal capacitor are different from each otherin level, thereby improving side visibility of the liquid crystaldisplay device.

An exemplary embodiment of the present invention provides, for example,a storage electrode line charge sharing driving method. In this drivingmethod, each pixel has, for example, three TFTs, one gate line, one dataline, and one storage electrode line. Gate electrodes of first andsecond TFTs are connected to the gate line, source electrodes thereofare connected to the data line, and drain electrodes thereof areconnected to terminals of first and second-subpixel liquid crystalcapacitors, respectively. Other terminals of the first andsecond-subpixel liquid crystal capacitors are each connected to theupper-plate common electrode. A gate electrode of a third TFT isconnected to the storage electrode line, a source electrode thereof isconnected to the second-subpixel liquid crystal capacitor's electrodethat is connected to the drain electrode of the second TFT, and a drainelectrode thereof is connected to an opposing electrode of the storageelectrode line or a drain electrode's extended portion of the third TFT.As a charged voltage of the second-subpixel liquid crystal capacitorshares charges with the drain electrode's extended portion of the thirdTFT by the voltage on the storage electrode line, a charged voltage ofthe second subpixel is lower than a charged voltage of the firstsubpixel. The voltage supplied to the storage electrode line may be, forexample, substantially the same as the voltage on the common electrode.

Now, an operation of the liquid crystal display device manufactured bythe aforementioned method will be described in detail. The liquidcrystal display device has the pixel PX structure shown in FIG. 3, andoperates in the method described in conjunction with FIG. 11. Each ofthe modes for manufacturing the liquid crystal display panel assembly300, e.g., SVA, SC-VA and polarized UV-VA modes, was distinguisheddepending on the method of forming the alignment films 291 and 292.However, after the liquid crystal display panel assembly 300 ismanufactured, the liquid crystal display device operates insubstantially the same way regardless of the mode used. Therefore, theoperation of the liquid crystal display device will be described belowwithout reference to the modes used to form the alignment films.

The liquid crystal display panel assembly 300 is assembled based on theSVA, SC-VA or polarized UV-VA mode, using the lower and upper displaypanels 100 and 200 having the pixel PX of FIG. 3. The liquid crystaldisplay device is manufactured by, for example, connecting the drivers400 and 500, the signal controller 600 and the gray level voltagegenerator 800 to the liquid crystal display panel assembly 300 asillustrated in FIG. 1. While no voltage is supplied to the pixel PX inthe liquid crystal display device, liquid crystal molecules 31 adjacentto the alignment films 291 and 292 have a specific pre-tilt angleslightly tilted with respect to the direction perpendicular to the lowerand upper display panels 100 and 200. If a data voltage is supplied tothe pixel electrode 191, the liquid crystal molecules 31 in the samedomain move in the same tilt direction. Because directions of the microbranches 197 of the first and second subpixel electrodes 191 h and 191 lare different from each other with respect to the transmission axis orpolarization axis of the polarizer, the strength of the fringe electricfield is different according to the widths of micro slits 199, voltagesof the liquid crystal capacitors are different, and the subpixelelectrodes 190 h and 190 l are different in luminance. By adjusting theliquid crystal's tilt angles of the subpixel electrodes 191 h and 191 lin this way, the side visibility of the liquid crystal display devicemay be increased. In addition, as the second subpixel electrode 191 lhas the MA region described above, the arrangement of the liquid crystalmolecules 31 may continuously change, thereby reducing the textureoccurring when the liquid crystal molecules 31 are aligneddiscontinuously.

Basic Pixel Group of Liquid Crystal Display Device

Now, with reference to FIGS. 12, 14, and 28 to 32, a basic pixel groupPS representing the primary colors according to an exemplary embodimentof the present invention will be described. This basic pixel group PSmay increase the visibility of the liquid crystal display device andreduce rainbow stains or the yellowish phenomenon, contributing toincrease of the quality of a liquid crystal display device having thisbasic pixel group. FIGS. 12, 14, and 28 to 32 are plan views of thepixel electrodes 191 of the basic pixel group PS of the liquid crystaldisplay device according to an exemplary embodiment of the presentinvention. FIGS. 12, 14, and 28 to 32 illustrate plan views of only thepixel electrodes of the basic pixel group PS formed on the lower displaypanel 100. As other plan views except the plan view of the pixelelectrode 191 are the same as above, a description thereof is omitted,as well as other duplicate descriptions.

As illustrated in FIG. 12, the basic pixel group PS is comprised of, forexample, pixel electrodes 191R, 191G and 191B corresponding to theprimary colors of red, green and blue. The pixel electrodes 191R and191G of red and green pixels PX are, for example, the same in structure,but the pixel electrode 191B of a blue pixel PX is partially differentin structure from the other pixel electrodes 191R and 191G. The basicpixel group PS includes, for example, red, green and blue pixels PXcorresponding to the 3 primary colors: red R, green G and blue B. Thered, green and blue pixels PX have the red, green and blue pixelelectrodes 191R, 191G and 191B, respectively. Color filters representingthe primary colors may be formed on the lower or upper display panel 100or 200. Each of the pixel electrodes 191R, 191G and 191B is, forexample, divided into two subpixel electrodes 191 h and 191 l formed intwo subpixel regions. The red pixel electrode 191R has a first redsubpixel electrode 191 hR formed in a first subpixel region of the redpixel and a second red subpixel electrode 191 lR formed in a secondsubpixel region of the red pixel. The green pixel electrode 191G has afirst green subpixel electrode 191 hG formed in a first subpixel regionof the green pixel and a second green subpixel electrode 191 lG formedin a second subpixel region of the green pixel. The blue pixel electrode191B has a first blue subpixel electrode 191 hB formed in a firstsubpixel region of the blue pixel and a second blue subpixel electrode191 lB formed in a second subpixel region of the blue pixel. A microbranch width and a micro slit width of each of the first red subpixelelectrode 191 hR and the first green subpixel electrode 191 hG is, forexample, about 3 μm and about 3 μm, respectively, and a micro branchwidth and a micro slit width of the first blue subpixel electrode 191 hBis, for example, about 3 μm and about 4 μm, respectively. A micro branchwidth and a micro slit width of each of the second red subpixelelectrode 191 lR, the second green subpixel electrode 191 lG and thesecond blue subpixel electrode 191 lB were, for example, about 3 μm andabout 3 μm, respectively. According to an exemplary embodiment of thepresent invention, the width of the micro slits of the first subpixelelectrode 191 hB in the blue pixel is, for example, greater than thewidths of the micro slits of the first subpixel electrodes 191 hR and191 hG and the second subpixel electrodes 191 lR, 191 lG and 191 lB inthe other pixels, thus reducing first subpixel's luminance in the bluepixel.

A direction of micro branches of each of the first red, green and bluesubpixel electrodes 191 hR, 191 hG and 191 hB is, for example, 03, whichis about 40°. A direction of micro branches of each of the second red,green and blue subpixel electrodes 191 lR, 191 lG and 191 lB is, forexample, 04, which is about 45°. Each of θ3 and θ4 is an angle withrespect to the polarization axis of the polarizer. If micro branchdirections of the first subpixel electrodes 191 hR, 191 hG and 191 hBand the second subpixel electrodes 191 lR, 191 lG and 191 lB are setdifferent in this way, luminance of the first subpixels and luminance ofthe second subpixels are adjusted. In each of the pixels constitutingthe basic pixel group, the area of the second subpixel is, for example,about 1.75 times that of the first subpixel.

Now, a description will be made of optical properties and effects of theliquid crystal display device having the pixel electrodes 191 of thebasic pixel group PS shown in FIG. 12. FIG. 13A is a graylevel-luminance ratio graph measured in a conventional liquid crystaldisplay device in which all of the pixel electrodes constituting a basicpixel group PS have the same structure. FIG. 13B is a graylevel-luminance ratio graph measured in the liquid crystal displaydevice having the pixel electrodes 191 of the basic pixel group PS shownin FIG. 12 according to an exemplary embodiment of the presentinvention. The liquid crystal display device according to an exemplaryembodiment of the present invention was manufactured based on the SVAmode and operated using the CS charging-based 1G1D driving. Further, inthe current exemplary embodiment of the present invention, the voltagecharged in the second subpixel electrode was, for example, about 0.77times the voltage charged in the first subpixel electrode, and the cellspacing in the liquid crystal layer was, for example, about 3.55 μm.

The horizontal axis of the gray level-luminance ratio graph represents agray level corresponding to a voltage supplied to the subpixelelectrodes 191 h and 191 l, and the vertical axis thereof represents aluminance ratio of the liquid crystal display device, which was measuredby a spectroscope on the right side of the liquid crystal display deviceat, for example, approximately 60°. The luminance ratio on the verticalaxis represents a ratio of gray level luminance to the maximum luminanceof each color, measured at the right side at, for example, approximately60°. Referring to a blue luminance curve B1 shown in FIG. 13A by way ofexample, if blue pixel's luminance is 100 candela (cd) at the highestgray level of 250, and 50 cd at a gray level of 150, the luminance ratioof the blue luminance curve B1 is about 0.5. Curves R1, G1, B1 and W1shown in FIG. 13A are luminance ratio curves of red light, green light,blue light and white light, respectively, measured in the conventionalliquid crystal display device. Curves R2, G2, B2 and W2 shown in FIG.13B are luminance ratio curves of red light, green light, blue light andwhite light, respectively, measured in the liquid crystal display deviceaccording to an exemplary embodiment of the present invention. Thewhite-light luminance W1 and W2 are sums of the red-light luminance R1and R2, the green-light luminance G1 and G2, and the blue-lightluminance B1 and B2. Ratios of the red-light luminance, green-lightluminance and blue-light luminance to the white-light luminance are, forexample, about 55% to about 65%, 20% to about 30% and 10% to about 20%,respectively.

As can be seen from the graph of FIG. 13A, in the medium gray levelportion A8 represented by an ellipse, the conventional red-lightluminance ratio curve R1 abruptly increases in slope, crossing theblue-light luminance ratio curve B1. After passing the point where thered-light luminance ratio curve R1 and the blue-light luminance ratiocurve B1 cross each other, the red-light luminance ratio is higher thanthe blue-light luminance ratio. In this gray level portion A8 where theblue-light luminance ratio becomes lower than the red-light luminanceratio, a yellowish color appears at the side of the liquid crystaldisplay device. If the yellowish color is visually perceived, the imagequality may be decreased and the color of the original image may bedisordered, thus deteriorating the display quality of the liquid crystaldisplay device. Therefore, it may be good to prevent the yellowish colorfrom being visually perceived. The luminance ratios of the primarycolors cross each other at a specific one of high gray levels, but atthe high gray levels, a luminance difference between gray levels islarge, so the yellowish color can be scarcely observed.

However, as illustrated in FIG. 13B, the liquid crystal display devicehaving the pixel electrodes of the basic pixel group PS according to anexemplary embodiment of the present invention does not have the pointwhere the red-light luminance ratio curve R1 and the blue-lightluminance ratio curve B1 cross each other, which was observed in theconventional liquid crystal display device. In the medium gray levelportion A8 represented by all ellipse in FIG. 13B, since the red-lightluminance ratio curve R2 and the blue-light luminance ratio curve B2 aresimilar in the slope, there is no point where the red-light luminanceratio and the blue-light luminance ratio cross each other. Therefore,the liquid crystal display device according to an exemplary embodimentof the present invention may not generate the yellowish color.

In addition, if luminance ratios among the primary colors change as theluminance ratios of different primary colors cross each other at aparticular gray level, the liquid crystal display device may cause colorerror or chromaticity shift. To correct this, the luminance ratios amongthe primary color pixels constituting the basic pixel group PS may bedesigned in balance.

FIG. 14 is a plan view of the pixel electrodes 191 of the basic pixelgroup PS of a liquid crystal display device according to an exemplaryembodiment of the present invention. FIG. 14 illustrates a plan view ofonly the pixel electrodes 191 of the basic pixel group PS formed on thelower display panel 100. As other plan views except the plan view of thepixel electrode 191 are the same as those described in FIG. 12, adescription thereof is omitted, and other duplicate descriptions arealso omitted except for the differences. The basic pixel group PSincludes, for example, red, green and blue pixels PX corresponding tothe three primary colors: red R, green G and blue B. In each of thepixels, pixel electrodes are formed, and each pixel electrode includes,for example, first and second subpixel electrodes.

For example, a micro branch width and a micro slit width of each of thefirst red subpixel electrode 191 hR and the first green subpixelelectrode 191 hG are about 3 μm and about 3 μm, respectively, and amicro branch width and a micro slit width of the first blue subpixelelectrode 191 hB are, respectively, about 3 μm and about 3 μm in the HAregion, about 3 μm and about 4 μm in the LA region, and about 3 μm andabout 3 μm to about 4 μm in the MA region. Micro branches 197 formed ineach domain are symmetrical about the horizontal and verticalcross-shaped branches 195. If the first blue subpixel electrode 191 hBis formed in this manner, the first blue subpixel is lower in luminancethan the first subpixels of other color pixels.

A micro branch width and a micro slit width of each of the second redsubpixel electrode 191 lR, the second green subpixel electrode 191 lGand the second blue subpixel electrode 191 lB are, respectively, forexample, about 3 μm and about 3 μm in the HA region, about 3 μm andabout 4 μm in the LA region, and about 3 μm and about 3 μm to about 4 μmin the MA region. The MA region included in each of the first and secondblue subpixel electrodes 191 hB and 191 lB, the second red subpixelelectrode 191 lR and the second green subpixel electrode 191 lG is aregion where the micro branch width is, for example, constant to about 3μm and the micro slit width, for example, gradually changes from about 3μm to about 4 μM. In each domain, the area of the HA region is, forexample, about 61% of the total area of the domain region, e.g., thecombined area of the HA region, LA region and the MA region. Inaddition, the area of the MA region is, for example, about 30% to about35% of the HA region's area. Micro branches 197 formed in each domain ineach subpixel are, for example, symmetrical about the horizontal andvertical cross-shaped branches 195. By forming the subpixel electrodesof the second subpixels in this manner, it is possible to adjustluminance of the second subpixels with respect to luminance of the firstsubpixels. In addition, as the MA regions are formed on the secondsubpixel electrodes, texture occurrence decreases and luminance of thesecond subpixels increases.

A direction of micro branches of each of the first red, green and bluesubpixel electrodes 191 hR, 191 hG and 191 hB is equal to, for example,θ5, which is about 40°. A direction of micro slits of each of the secondred, green and blue subpixel electrodes 191 lR, 191 lG and 191 lB isequal to, for example, θ6, which is about 45°. Each of θ5 and θ6 is anangle with respect to the polarization axis of the polarizer. As anglesof θ5 and θ6 are formed different, the luminance of the first and secondsubpixels may be adjusted, thereby increasing the side visibility of theliquid crystal display device.

By differentiating the micro slit width of the first subpixel electrode191 hB of the blue pixel electrode 191B from those of the first subpixelelectrodes of other color pixels as illustrated in FIG. 14, theyellowish phenomenon of the liquid crystal display device may beprevented.

Unlike the exemplary embodiments shown in FIGS. 12 and 14, one pixelelectrode other than the blue pixel electrode may be formed different instructure from other pixel electrodes.

In an exemplary embodiment of the present invention, micro branches 197formed in each domain may be, for example, symmetrical about any one ofthe horizontal and vertical cross-shaped branches 195. For example,micro branches 197 formed in each domain may be, for example,symmetrical about the horizontal cross-shaped branch 195.

In an exemplary embodiment of the present invention, the basic pixelgroup PS may be comprised of, for example, four or more colors,including the yellow color. To increase the color quality of the liquidcrystal display device, the structure of two or more primary colors'pixel electrodes 191 may be formed, for example, different from thestructure of the other one primary color's pixel electrode 191 in thebasic pixel group PS comprised of four or more primary colors.

A pixel electrode structure of a basic pixel group (PS) will bedescribed in detail below with reference to FIGS. 28 to 32. Microbranches 197 and micro slits 199 illustrated FIGS. 28 to 32 have, forexample, a zigzag shape. An area ratio of a first subpixel electrode 191h 28 to a second subpixel electrode 191 l 28 may fall within a range of,for example, about 1:2 to about 1:1.5. Duplicate descriptions will beomitted hereinafter.

According to an exemplary embodiment of the present invention, a basicpixel group PS illustrated in FIG. 28 includes different structures ofpixel electrodes corresponding to pixels having different primarycolors. The primary colors include, for example, a red color R, a greencolor G and a blue color B, and they constitute red, green and bluepixels PXs, respectively. On a red pixel PX is formed a red pixelelectrode 191R28, which includes first and second subpixel electrodes191Rh28 and 191Rl28. On a green pixel PX is formed a green pixelelectrode 191G28, which includes first and second subpixel electrodes191Gh28 and 191Gl28. On a blue pixel PX is formed a blue pixel electrode191B28, which includes first and second subpixel electrodes 191Bh28 and191Bl28. For example, first subpixel electrodes 191Bh28, 191Gh28, and191Rh28 of pixel electrodes, e.g., red, green and blue pixel electrodes191R28, 191G28, and 191B28 of the basic pixel group, each have fourdomain regions Dh1, Dh2, Dh3, and Dh4, and also, second subpixelelectrodes 191Bl28, 191Gl28, and 191Rl28 thereof each have four domainregions Dl1, Dl2, Dl3, and Dl4.

Micro branches 197 and micro slits 199 constituting pixel electrodes ofthe primary colors may, for example, be different in widths in differentpixel electrodes of the primary colors. For example, in eight domainsDh1, Dh2, Dh3, Dh4, Dl1, Dl2, Dl3, and Dl4 formed on first and secondsubpixel electrodes 191Rh28 and 191Rl28 of the red pixel electrode191R28, widths S and W of micro branches 197 and micro slits 199gradually increase in the arrow directions illustrated in FIG. 28 fromabout 3.4 μm to about 4.2 μm by a value falling within a range of about0.2 μm to about 0.5 μm. In eight domains Dh1, Dh2, Dh3, Dh4, Dl1, Dl2,Dl3, and Dl4 formed on first and second subpixel electrodes 191Gh28 and191Gl28 of the green pixel electrode 191G28, widths S and W of microbranches 197 and micro slits 199, for example, gradually increase in thearrow directions illustrated in FIG. 28 from about 3 μm to about 3.8 μmby a value falling within a range of about 0.4 μm to about 0.5 μm. Ineight domains Dh1, Dh2, Dh3, Dh4, Dl1, Dl2, Dl3, and Dl4 formed on firstand second subpixel electrodes 191Bh28 and 191Bl28 of the blue pixelelectrode 191B28, widths S and W of micro branches 197 and micro slits199, for example, gradually increase in the arrow directions illustratedin FIG. 28 from about 2.5 μm to about 4 μm by a value falling within arange of about 0.2 μm to about 0.5 μm. In accordance with an exemplaryembodiment of the present invention, each of domains Dh1˜Dh4, andDl1˜Dl4 is divided into a plurality of groups, which have micro brancheswith the same widths S and micro slits with the same widths W, and inwhich widths of micro branches and micro slits may increase along groupsin the arrow directions.

Main directions, zigzag angles and zigzag unit lengths of zigzag-shapedmicro branches 197 will be described below. For example, in domains Dh1and Dh2 formed on first subpixel electrodes 191Rh28, 191Gh28, and191Bh28 of pixel electrodes 191R28, 191G28, and 191B28 in the basicpixel group, a zigzag unit length is about 20 μm, main direction anglesof micro branches 197 are about 40°, and a zigzag angle graduallyincreases in the arrow directions illustrated in FIG. 28 from about ±0°to about ±12° by a value falling within a range of about 0.5° to about1°. In domains Dh3 and Dh4 formed on first subpixel electrodes 191Rh28,191Gh28, and 191Bh28 of pixel electrodes 191R28, 191G28, and 191B28 inthe basic pixel group, for example, a zigzag unit length is about 7 μm,main direction angles of micro branches 197 are about 40°, and a zigzagangle is about ±15°. In domains Dl1 and Dl2 formed on second subpixelelectrodes 191Rl28, 191Gl28, and 191Bl28 of red, green and blue pixelelectrodes 191R28, 191G28 and 191B28, for example, a zigzag unit lengthis about 20 μm, main direction angles of micro branches 197 are about45°, and a zigzag angle is about ±15°. In domains Dl3 and Dl4 formed onsecond subpixel electrodes 191Rl28, 191Gl28, and 191Bl28 of pixelelectrodes 191R28, 191G28, and 191B28 in the basic pixel group, forexample, a zigzag unit length is, about 14 μm, main direction angles ofmicro branches 197 are about 45°, and zigzag angles gradually increasein the arrow directions illustrated in FIG. 28 from about ±0° to about±15° by a value falling within a range of about 0.5° to about 1°. Maindirections, zigzag angles and zigzag unit lengths of micro branches 197formed in domains Dh1, Dh2, Dh3, Dh4, Dl1, Dl2, Dl3 and Dl4 constitutingthe green pixel electrode 191G28 are, for example, equal to maindirections, zigzag angles and zigzag unit lengths of micro branches 197formed in domains constituting the red and blue pixel electrodes 191R28and 191B28. In accordance with an exemplary embodiment of the presentinvention, in pixel electrodes 191R28, 191G28, and 191B28 of the basicpixel group, pixel electrode structures in domains Dh1, Dh4, Dl1, andDl4 formed at the left of cross-shaped branch's vertical portions 195 vmay be, for example, symmetrical to pixel electrode structures indomains Dh2, Dh3, Dl2, and Dl3 formed at the right of the cross-shapedbranch's vertical portions 195 v about the vertical portions 195 v. Thebasic pixel group constructed with these pixel electrodes may increasevisibility of the liquid crystal display device, prevent the yellowishcolor from being visible, and significantly reduce rainbow stains bydispersing diffraction spots of light diffracted in the liquid crystaldisplay device.

Each of pixel electrode junction connection portions formed on firstsubpixel electrodes 191Rh28, 191Gh28, and 191Bh28 has, for example, apixel electrode's vertical connection portion 715 h that connects afirst pixel electrode contact portion 192 h to a cross-shaped branch'svertical portion 195 v. Each of pixel electrode junction connectionportions formed on second subpixel electrodes 191Rl28, 191Gl28, and191Bl28 has, for example, a pixel electrode's horizontal connectionportion 713 l connected to a second pixel electrode contact portion 192l, and a pixel electrode's oblique connection portion 714 l thatconnects the pixel electrode's horizontal connection portion 713 l to across-shaped branch's vertical portion 195 v. These pixel electrodejunction connection portions may reduce liquid crystal molecule'sunrestoration and light leakage defects.

Domains formed on pixel electrodes constituting a basic pixel groupillustrated in FIG. 29 have, for example, different main directions andthe same zigzag angle according to an exemplary embodiment of thepresent invention. Widths of micro branches 197 and micro slits 199illustrated in FIG. 29 are, for example, equal in domains formed on thesame subpixels. In other words, widths of micro branches 197 and microslits 199 are uniformly distributed in all domains Dh1, Dh2, Dh3, andDh4 formed on first subpixels, and widths of micro branches 197 andmicro slits 199 are uniformly distributed in all domains Dl1, Dl2, Dl3,and Dl4 formed on second subpixels. However, widths of micro branches197 or micro slits 199 formed in domains of first subpixels are, forexample, different from those in domains of second subpixels. Forexample, in domains Dh1, Dh2, Dh3, and Dh4 formed on first subpixelelectrodes 191Rh29, 191Gh29, and 191Bh29 of pixel electrodes 191R29,191G29, and 191B29 in the basic pixel group, widths S and W of microbranches 197 and micro slits 199 gradually increase in the arrowdirections illustrated in FIG. 29 from about 2.5 μm to about 3.2 μm by avalue falling within a range of about 0.2 μm to about 0.5 μm. In domainsDl1, Dl2, Dl3, and Dl4 formed on second subpixel electrodes 191Rl29,191Gl29, and 191Bl29 of pixel electrodes 191R29, 191G29, and 191B29 inthe basic pixel group, widths S and W of micro branches 197 and microslits 199 gradually increase in the arrow directions illustrated in FIG.29 from about 2.5 μm to about 3.5 μm by a value falling within a rangeof about 0.4 μm to about 0.5 μm. In accordance with an exemplaryembodiment of the present invention, each of domains Dh1 to Dh4, and Dl1to Dl4 is divided into, for example, a plurality of groups, which havemicro branches with the same widths and micro slits with the samewidths, and in which widths of micro branches and micro slits mayincrease along groups in the arrow directions.

Main directions, zigzag angles and zigzag unit lengths of zigzag-shapedmicro branches 197 will be described below. Zigzag unit lengths are, forexample, about 14 μm in domains Dh1, Dh2, Dh3 and Dh4 formed on firstsubpixel electrodes 191Rh29, 191Gh29, and 191Bh29 of pixel electrodes191R29, 191G29, and 191B29 in the basic pixel group, and about 10 μm indomains Dl1, Dl2, Dl3 and Dl4 formed on second subpixel electrodes191Rl29, 191Gl29, and 191Bl29. In domains Dh1, Dh2, Dh3 and Dh4 formedon first subpixel electrodes 191Rh29 and 191Gh29 of red and green pixelelectrodes 191R29 and 191G29, and domains Dl1, Dl2, Dl3 and Dl4 formedon a second subpixel 191Bl29 of a blue pixel electrode 191B29, maindirection angles of micro branches 197 are, for example, about 50°,about 48°, about 40°, and about 41.3°, respectively, and zigzag anglesare about ±15° in each domain. In domains Dl1, Dl2, Dl3 and Dl4 formedon second subpixel electrodes 191Rl29 and 191Gl29 of red and green pixelelectrodes 191R29 and 191G29, and domains Dh1, Dh2, Dh3 and Dh4 formedon a first subpixel electrode 191Bh29 of a blue pixel electrode 191B29,main direction angles of micro branches 197 are, for example, about 42°,about 40.8°, about 48°, and about 49.2°, respectively, and zigzag anglesare, for example, about ±15° in each domain.

The basic pixel group PS having primary colors, the pixel electrodes191R29, 191G29, and 191B29 including first subpixel electrodes 191Rh29,191Gh29, and 191Bh29 and second subpixel electrodes 191Rl29, 191Gl29,and 191Bl29, the pixel electrodes divided into, for example, domainregions Dh1, Dh2, Dh3, Dh4, Dl1, Dl2, Dl3, and Dl4, the zigzag-shapedmicro branches 197, and the area ratios of first subpixel electrodes tosecond subpixel electrodes are substantially similar to those describedabove or in connection with FIG. 28. The basic pixel group constructedwith these pixel electrodes has the characteristics described inconnection with FIG. 28. Pixel electrode junction connection portionsformed on first and second subpixel electrodes 191Rh29, 191Gh29,191Bh29, 191Rl29, 191Gl29, and 191Bl29 are similar to those describedwith reference to FIGS. 23C and 24C.

According to an exemplary embodiment of the present invention, in pixelelectrodes constituting a basic pixel group PS illustrated in FIG. 30,each of domains Dl1, Dl2, Dl3, and Dl4 on second subpixel electrodes191Rl30, 191Gl30, and 191Bl30 has, for example, a plurality ofsubdomains, micro branches and micro slits in each subdomain have thesame widths, and a width between adjacent subdomains is greater than thewidths of micro branches or micro slits in each subdomain. However, indomains Dh1 to Dh4 on first subpixel electrodes 191Rh30, 191Gh30, and191Bh30, widths of micro branches and micro slits may, for example,gradually increase in the arrow directions. For example, in domains Dh1,Dh2, Dh3, and Dh4 formed on first subpixel electrodes 191Rh30 and191Gh30 of red and green pixel electrodes 191R30 and 191G30, widths Sand W of micro branches 197 and micro slits 199 gradually increase inthe arrow directions illustrated in FIG. 30 from about 2.8 μm to about3.3 μm by a value falling within a range of about 0.2 μm to about 0.5μm. In domains Dh1, Dh2, Dh3, and Dh4 formed on a first subpixelelectrode 191Bh30 of a blue pixel electrode 191B30, widths S of microbranches 197, for example, gradually increase in the arrow directionsillustrated in FIG. 30 from about 2.8 μm to about 3.3 μm by a valuefalling within a range about 0.2 μm to about 0.5 μm, and widths W ofmicro slits 199 gradually increase from about 3.8 μm to about 4.0 μm. Inaccordance with an exemplary embodiment of the present invention, eachof domains Dh1 to Dh4, and Dl1 to Dl4 is divided into, for example, aplurality of groups, which have micro branches with the same widths andmicro slits with the same widths.

In subdomains of domains Dl1, Dl2, Dl3, and Dl4 on second subpixelelectrodes 191Rl30, 191Gl30, and 191Bl30 of pixel electrodes 191R30,191G30, and 191B30 in the basic pixel group, widths S and W of microbranches 197 and micro slits 199 are, for example, about 3.0 μm,respectively. For example, a width of each subdomain in each domain isabout 27 μm, and an interval between adjacent subdomains in each domainis about 4.5 μm. Domains Dl3 and Dl4 formed on second subpixelelectrodes 191Rl30, 191Gl30, and 191Bl30 may have, for example,subdomains in which widths S and W of most micro branches 197 and microslits 199 are about 3.0 μm, and micro slits 199 include a width, forexample, a width of about 4.5 μm, different from the width S of theiradjacent micro slits 199, at intervals of a specific distance, forexample, about 27 μm. In accordance with an exemplary embodiment of thepresent invention, micro branches 197 or micro slits 199 having, forexample, a width greater than a width of their adjacent micro branches197 or micro slits 199 may be formed in domains Dh1, Dh2, Dh3, Dh4, Dl1,Dl2, Dl3, and Dl4 constituting first or second subpixel electrode, atintervals of a specific distance. Zigzag unit lengths are, for example,about 10 μm in domains Dh1, Dh2, Dh3 and Dh4 formed on first subpixelelectrodes 191Rh30, 191Gh30, and 191Bh30 of pixel electrodes 191R30,191G30, and 191B30 in the basic pixel group, and about 7 μm in domainsDl1, Dl2, Dl3 and Dl4 formed on second subpixel electrodes 191Rl30,191Gl30, and 191Bl30. Main directions and zigzag angles of microbranches 197 formed in domains of the basic pixel group are, forexample, substantially similar to those described in connection withFIG. 29.

The basic pixel group PS having primary colors, the pixel electrodes191R30, 191G30, and 191B30 including first subpixel electrodes 191Rh30,191Gh30, and 191Bh30 and second subpixel electrodes 191Rl30, 191Bl30,and 191Bl30, the pixel electrodes divided into domains Dh1, Dh2, Dh3,Dh4, Dl1, Dl2, Dl3, and Dl4, the zigzag-shaped micro branches 197, andthe area ratios of first subpixel electrodes to second subpixelelectrodes are, for example, substantially similar to those describedabove or in connection with FIG. 28. The basic pixel group constructedwith these pixel electrodes has, for example, the characteristicsdescribed in connection with FIG. 28. Pixel electrode junctionconnection portions formed on first and second subpixel electrodes191Rh30, 191Gh30, 191Bh30, 191Rl30, 191Gl30, and 191Bl30 are, forexample, similar to those described with reference to FIGS. 23F and 24C.

In a basic pixel group PS illustrated in FIG. 31, main direction anglesof micro branches 197 are greater in domains formed on second subpixelelectrodes 191Rl31, 191Gl31, and 191Bl31 rather than in domains formedon first subpixel electrodes 191Rh31, 191Gh31, and 191Bh31 according toan exemplary embodiment of the present invention. For example, indomains Dh1 and Dh2 on first subpixel electrodes 191Rh31, 191Gh31, and191Bh31 of pixel electrodes 191R31, 191G31, and 191B31 in the basicpixel group, a zigzag unit length is about 14 μm, main direction anglesof micro branches 197 are about 40.8°, and a zigzag angle is about 10°.In domains Dh3 and Dh4 thereof, for example, a zigzag unit length isabout 14 μm, main direction angles of micro branches 197 are about39.2°, and a zigzag angle is about 10°. In domains Dl1 and Dl2 on secondsubpixel electrodes 191Rl31, 191Gl31, and 191Bl31 of pixel electrodes191R31, 191G31, 191B31 in the basic pixel group, for example, a zigzagunit length is about 10 μm, main direction angles of micro branches 197are about 42°, and a zigzag angle is about 15°. In domains Dl3 and Dl4thereof, for example, a zigzag unit length is about 10 μm, maindirection angles of micro branches 197 are about 41.3°, and a zigzagangle is about 15°. Main direction angles of micro branches 197 may bean angle with respect to the direction D1.

In domains Dh1, Dh2, Dh3, and Dh4 formed on first subpixel electrodes191Rh31, and 191Gh31 of red and green pixel electrodes 191R31 and191G31, widths S and W of micro branches 197 and micro slits 199, may,for example, gradually increase in the arrow directions illustrated inFIG. 31 from about 2.8 μm to about 3.3 μm by a value falling within arange of about 0.2 μm to about 0.5 μm. In domains Dh1. Dh2, Dh3, and Dh4formed on a first subpixel electrode 191Bh31 of a blue pixel electrode191B31, for example, widths S and W of micro branches 197 and microslits 199 gradually increase in the arrow directions illustrated in FIG.31 from 3.3 μm to about 3.7 μm by a value falling within a range ofabout 0.2 μm to about 0.5 μm. In domains Dl1, Dl2, Dl3, and Dl4 onsecond subpixel electrodes 191Rl31, 191Gl31, and 191Bl31 of pixelelectrodes 191R31, 191G31, and 191B31, for example, widths S and W ofmicro branches 197 and micro slits 199 gradually increase in the arrowdirections illustrated in FIG. 31 from about 2.8 μm to about 3.9 μm by avalue falling within a range of about 0.2 μm to about 0.5 μm. Inaccordance with an exemplary embodiment of the present invention, eachof domains Dh1 to Dh4, and Dl1 to Dl4 is, for example, divided into aplurality of groups, which have micro branches with the same widths andmicro slits with the same widths, and in which widths of micro branchesand micro slits may increase along groups in the arrow directions. Othercomponents are similar to those described in connection with FIG. 28, soa description thereof is omitted. Pixel electrode junction connectionportions formed on first and second subpixel electrodes 191Rh31,191Gh31, 191Bh31, 191Rl31, 191Gl31, and 191Bl31 are, for example,similar to those described with reference to FIG. 20C.

In accordance with an exemplary embodiment of the present invention, abasic pixel group PS illustrated in FIG. 32 includes, for example, fourpixels PX having the structures described in connection with FIGS. 25 to27B, in which longer sides of pixel electrodes are formed in parallel toa gate line 121. In accordance with an exemplary embodiment of thepresent invention, the four pixels PX illustrated in FIG. 32 have, forexample, four different primary colors—red R, green G, blue B and whiteW—and include red, green, blue and white pixel electrodes 191R32,191G32, 191B32 and 191W32. The pixel electrodes 191R32, 191G32, 191B32and 191W32 include, for example, first subpixel electrodes 191Rh32,191Gh32, 191Bh32, and 191Wh32, and second subpixel electrodes 191Rl32,191Gl32, 191Bl32, and 191Wl32. Each of the first subpixel electrodeshas, for example, four domain regions Dh1, Dh2, Dh3, and Dh4, and eachof the second subpixel electrodes has four domain regions Dl1, Dl2, Dl3,and Dl4. For example, first subpixel electrodes of the red, green andwhite pixel electrodes 191R32, 191G32 and 191W32 are equal in structure,and a first subpixel electrode of the blue pixel electrode 191B32 isdifferent from the first subpixel electrodes of pixel electrodes havingother colors. For example, widths S and W of micro branches 197 andmicro slits 199 formed in domains of the first subpixel electrodes191Rh32, 191Gh32 and 191Wh32 may fall within a range of about 5 μm toabout 5.6 μm, and they may have different sizes in one domain. Inaccordance with an exemplary embodiment of the present invention, widthsS and W of micro branches 197 and micro slits 199 formed in domains offirst subpixel electrodes 191Rh32, 191Gh32 and 191Wh32 may, for example,gradually increase in the arrow directions illustrated in FIG. 32.Widths S and W of micro branches 197 and 199 formed in domains of afirst subpixel electrode 191Bh32 may fall, for example, within a rangeof about 6 μm to about 6.8 μm, or may have different sizes. Inaccordance with an exemplary embodiment of the present invention, widthsS and W of micro branches 197 and micro slits 199 formed in domains ofthe first subpixel electrode 191Bh32 may, for example, graduallyincrease in the arrow directions illustrated in FIG. 32. In accordancewith an exemplary embodiment of the present invention, widths S of microbranches 197 formed in domains of the first subpixel electrode 191Bh32are, for example, greater than widths S of micro branches 197 formed indomains of the first subpixel electrodes 191Rh32, 191Gh32 and 191Wh32.Widths W of micro slits 199 formed in domains of the first subpixelelectrode 191Bh32 are, for example, greater than widths W of micro slits199 formed in domains of the first subpixel electrodes 191Rh32, 191Gh32and 191Wh32.

Second subpixel electrodes of the red, green and white pixel electrodes191R32, 191G32 and 191W32 are, for example, equal in structure. Forexample, widths S and W of micro branches 197 and micro slits 199 formedin domains of second subpixel electrodes 191Rl32, 191Gl32, 191Bl32 and191Wl32 may fall within a range of about 5 μm to about 6.8 μm, and theymay have different sizes in one domain. Widths S and W of micro branches197 and micro slits 199 may, for example, gradually increase in thearrow directions illustrated in FIG. 32. Main directions, zigzag anglesand zigzag unit lengths of zigzag-shaped micro branches 197 aredescribed below. In domains Dh1, Dh2, Dh3 and Dh4 formed on firstsubpixel electrodes 191Rh32, 191Gh32, 191Bh32, and 191Wh32 of pixelelectrodes 191R32, 191G32, 191B32, and 191W32 in the basic pixel group,for example, a zigzag unit length is about 14 μm, main direction anglesof micro branches 197 may be about 40.8° or about 39.2°, and a zigzagangle may be about ±7°. In domains Dh1, Dh2, Dh3 and Dh4 formed onsecond subpixel electrodes 191Rl32, 191G132, 191Bl32, and 191Wl32, forexample, a zigzag length is about 10 μm, main direction angles of microbranches 197 may be about 42° or about 41.3°, and a zigzag angle may beabout ±5°. The basic pixel group constructed with these pixel electrodesmay not only have the characteristics of the basic pixel group describedin connection with FIG. 28, but also may increase transmittance of theliquid crystal display device. Pixel electrode junction connectionportions formed on first subpixel electrodes 191Rh32, 191Gh32, 191Bh32,and 191Wh32 are, for example, similar to those described with referenceto FIG. 23B, while pixel electrode junction connection portions formedon second subpixel electrodes 191Rl32, 191Gl32, 191Bl32, and 191Wl32 areconnected to pixel electrode contact portions extending in the directionof a gate line, and are substantially similar to those described withreference to FIG. 23A. In accordance with an exemplary embodiment of thepresent invention, the primary colors may include, for example, red,green, blue and yellow colors.

Shapes of pixel electrodes, splitting of pixel electrodes, partitioningof domains, and structures of basic pixel groups will be described indetail below with reference to FIGS. 33A to 33I. For convenience ofdescription, shapes of pixel electrodes illustrated in FIGS. 33A to 33Imay be represented by contours of pixel electrodes or splitting of pixelelectrodes. Other parts of pixel electrodes, for example, pixelelectrode contact portions, micro branches 197 and micro slits 199, willbe described in FIGS. 33A to 33I, as well. The structures and methodsdescribed with reference to FIGS. 3, 5, 12, 14, 16, 17, 18, 20, 23, 24,25 and 28 to 32, may be applied to pixel electrodes illustrated in FIGS.33A to 33I.

First, shapes and splitting of pixel electrodes will be described indetail with reference to FIGS. 33A to 33F. Each of the pixel electrodesillustrated in FIGS. 33A to 33F includes a first subpixel electrode 191h and a second subpixel electrode 191 l. Each of the subpixel electrodes191 h and 191 l may receive a data voltage by the above-described datavoltage reception method, and the first subpixel electrode 191 h may be,for example, higher than the second subpixel electrode 191 l in terms ofthe charging voltage thereon. Referring to FIG. 33A, a first subpixelelectrode 191 h has, for example, four domains, and a second subpixelelectrode 191 l has, for example, eight domains. In other words, forexample, the first subpixel electrode 191 h has domains Dha, Dhb, Dhcand Dhd, and the second subpixel electrode 191 l has domains Dla, Dlb,Dlc, Dld, Dle, Dlf, Dlg and Dlh. The structure of the second subpixelelectrode 191 l formed in this way may increase the visibility of theliquid crystal display device. The second subpixel electrode 191 l maybe, for example, greater in area than the first subpixel electrode 191h. Domains thereof may have the above-described structure. Referring toFIGS. 33B to 33F, each of first and second subpixel electrodes 191 h and191 l includes, for example, four domains. In other words, for example,the first subpixel electrode 191 h has domains Dha, Dhb, Dhc and Dhd,and the second subpixel electrode 191 l has domains Dla, Dlb, Dlc andDld. Sides of first and second subpixel electrodes 191 h and 191 lillustrated in FIG. 33B may be oblique lines extending in the directionof a data line 171. The oblique lines may be, for example, substantiallyin parallel to a transmission axis of a polarizer. Domains of the firstand second subpixel electrodes 191 h and 191 l may be in the shape of,for example, a parallelogram. The pixel electrode formed in this way mayincrease the visibility and transmittance of the liquid crystal displaydevice. First and second subpixel electrodes 191 h and 191 l illustratedin FIGS. 33C to 33F are adjacent to each other by oblique sides thereof.The oblique directions may be, for example, substantially in parallel toa transmission axis of a polarizer. The structure of a pixel electrodeformed in this way may increase the visibility and transmittance of theliquid crystal display device. In the structure of pixel electrodesillustrated in FIGS. 33D to 33F, any one of first and second subpixelelectrodes 191 h and 191 l substantially accommodates the other one. Ifboundary sides between adjacent subpixel electrodes are large in area,or domains of first and second subpixel electrodes 191 h and 191 l areuniformly distributed in this manner, the visibility of the liquidcrystal display device may be increased. A first subpixel electrode 191h illustrated in FIG. 33D is split into, for example, two, bordering ona second subpixel electrode 191 l. A second subpixel electrode 191 lillustrated in FIG. 33E, for example, substantially surrounds a firstsubpixel electrode 191 h, and a first subpixel electrode 191 hillustrated in FIG. 33F substantially surrounds a second subpixelelectrode 191 l. For example, the second subpixel electrode 191 lillustrated in FIG. 33F is diamond-shaped, and domains thereof aretriangular.

Structures of basic pixel groups PS will be described in detail belowwith reference to FIGS. 33G to 33I. Each of the basic pixel groups PSillustrated in FIGS. 33G to 33I includes, for example, four pixels PXa,PXb, PXc, and PXd having four different primary colors. The four primarycolors may include, for example, red, green, blue and yellow or whitecolors. A pixel PXa may have, for example, a red color, a pixel PXb mayhave a green colon a pixel PXc may have a blue color, and a pixel PXdmay have a yellow or white color. The basic pixel groups PS formed inthis way may increase the color reproducibility, transmittance andvisibility of the liquid crystal display device. In accordance with anexemplary embodiment of the present invention, the primary colors mayinclude a variety of colors as described above. The pixels PXa, PXb, PXcand PXd illustrated in FIG. 33G have red, green, blue and white colorsin order, thereby increasing the transmittance of the liquid crystaldisplay device. The pixels PXa, PXb, PXc and PXd illustrated in FIG. 33Hhave red, green, blue and yellow colors in order, thereby increasing thecolor reproducibility and display quality of the liquid crystal displaydevice. In addition, to further increase the color reproducibility anddisplay quality of the liquid crystal display device, an area ratio ofthe red, green, blue and yellow pixels may be, for example, about 1.4 toabout 1.8:1.0 to about 1.3:1.4 to about 1.8:1 (e.g., about1.6:1.1:1.6:1). The basic pixel group PS including pixels PXa, PXb, PXcand PXd illustrated in FIG. 33I is similar to, for example, thatdescribed in connection with FIG. 32. The pixels in FIG. 33I may be, forexample, substantially identical in area.

As is apparent from the foregoing description, according to an exemplaryembodiments of the present invention, the side visibility of the liquidcrystal display device may be increased and the display quality thereofmay also be increased.

The liquid crystal display device and the alignment film provided byexemplary embodiments of the present invention may increase thealignment properties of liquid crystal molecules and the reliability ofthe alignment film, thereby ensuring the excellent display quality ofthe liquid crystal display device.

Having described exemplary embodiments of the present invention, it isfurther noted that it is readily apparent to those of ordinary skill inthe art that various modifications may be made without departing fromthe spirit and scope of the invention which is defined by the metes andbounds of the appended claims.

What is claimed is:
 1. An alignment film comprising: a first pre-tiltfunctional group, a second pre-tilt functional group and a firstvertical alignment functional group, which are linked to polysiloxane ona substrate; wherein the first vertical alignment functional groupincludes a cyclic group and is aligned substantially perpendicularly tothe substrate; wherein the first pre-tilt functional group iscross-linked to the second pre-tilt functional group and tilted withrespect to the substrate, wherein the alignment film further comprisesan aggregation inhibitor linked to the polysiloxane.
 2. The alignmentfilm of claim 1, wherein a mol % composition ratio of the first verticalalignment functional group and the first pre-tilt functional group isabout 1:about 1.5 to about
 11. 3. The alignment film of claim 2, whereinthe first pre-tilt functional group is greater than the second pre-tiltfunctional group in chain length.
 4. The alignment film of claim 3,further comprising a second vertical alignment functional group linkedto the polysiloxane, wherein the second vertical alignment functionalgroup does not include a cyclic group.
 5. The alignment film of claim 2,further comprising a second vertical alignment functional group linkedto the polysiloxane, wherein the second vertical alignment functionalgroup does not include a cyclic group.
 6. The alignment film of claim 2,wherein the first vertical alignment functional group includes any oneof an alkyl benzene group, a cholesteric group, an alkylated alicyclicgroup, or an alkylated aromatic group.
 7. The alignment film of claim 1,wherein the first pre-tilt functional group is greater than the secondpre-tilt functional group in chain length.
 8. The alignment film ofclaim 7, further comprising a second vertical alignment functional grouplinked to the polysiloxane, wherein the second vertical alignmentfunctional group does not include a cyclic group.
 9. The alignment filmof claim 7, wherein the first and second pre-tilt functional groups eachinclude a different one of a vinyl group, a styrene group, amethacrylate group, a cinnamate group, or an acrylic group.
 10. Thealignment film of claim 7, wherein a mol % composition ratio of thefirst vertical alignment functional group, the first pre-tilt functionalgroup, and the second pre-tilt functional group is about 1:about 1.5 toabout 11:about 1 to about
 3. 11. The alignment film of claim 1, whereina mol % composition ratio of the first vertical alignment functionalgroup, the first pre-tilt functional group, and the aggregationinhibitor is about 1:about 1.5 to about 11:about 0.5 to about
 4. 12. Thealignment film of claim 1, further comprising a second verticalalignment functional group linked to the polysiloxane, wherein thesecond vertical alignment functional group does not include a cyclicgroup.
 13. The alignment film of claim 12, wherein a mol % compositionratio of the first vertical alignment functional group, the secondvertical alignment functional group, and the first pre-tilt functionalgroup is about 1:about 0.3 to about 3:about 1.5 to about
 11. 14. Aliquid crystal display device comprising: a liquid crystal layerincluding liquid crystal molecules and interposed between a firstdisplay panel and a second display panel; and an alignment film formedon at least one of the first and second display panels, wherein thealignment film includes a first pre-tilt functional group, a secondpre-tilt functional group and a first vertical alignment functionalgroup, which are linked to polysiloxane; wherein the first verticalalignment functional group includes a cyclic group and is configured toalign first liquid crystal molecules among the liquid crystal moleculesto be substantially perpendicular to the first or second display panels;wherein the first pre-tilt functional group is cross-linked to thesecond pre-tilt functional group and is configured to align secondliquid crystal molecules among the liquid crystal molecules to be tiltedwith respect to the first or second display panels, wherein thealignment film further comprises an aggregation inhibitor linked to thepolysiloxane.